Friedrich Air Conditioner How to & Troubleshooting Guide

The Friedrich air conditioner is most certainly one of the best air conditioner brands in the market. This can be attributed to its high-quality external and internal parts. its energy efficiency features like the programmable thermostat, its lower operation noise level, and its lower cost of maintenance and operation make it a worthy investment.

But even the best electronic gadget is bound to break down from time to time. So keep reading to learn how to troubleshoot and fix your Friedrich air conditioner. The article will also teach you how to use your air conditioner efficiently.

Why is my Friedrich Air Conditioner Not Working?

Below are reasons why your air conditioner is not working;

Clogged Air Filter

If the air filter is clogged, air cannot flow properly through the air conditioner. This greatly reduces the cooling capacity of the air conditioner. In addition, if the air filter is clogged, the evaporator coils will frost over. To remove debris from the air filter, try cleaning the filter. If it is not possible to clean the air filter, replace it.

Dirty Condenser Coils

The condenser coils dissipate the heat as the refrigerant passes through the coils. If the condenser coils are dirty, they won’t be able to dissipate the heat as effectively. As debris builds up on the coils, the air conditioner will become less efficient, causing the air conditioner to work harder to cool down.

If the coils are significantly dirty, the air conditioner will not be able to maintain the proper temperature, and the compressor will run continuously in an attempt to cool the room. Check the condenser coils to determine if they are dirty. If the condenser coils are dirty, clean them.

Defective Compressor

The compressor might be defective. However, this is not usually the case. Before replacing the compressor, check more commonly defective components—particularly the overload protector and the compressor capacitor. If the compressor is defective, it should only be replaced by a licensed technician.

Defective Thermostat

The thermostat monitors the temperature of the air. When the air temperature rises above a set point, the thermostat activates a switch to provide power to the fan and compressor. If the thermostat is defective, the thermostat may not cool properly.

To determine if the thermostat is defective, set the air conditioner to cooling and then use a multimeter to test the thermostat for continuity. If the thermostat does not have continuity while the air conditioner is set to cooling, replace the thermostat.

Faulty Control Board

The control board regulates the voltage to the compressor and the fan motor. If the control board fails, some components will not function properly or will not work at all. Control boards are often misdiagnosed; make sure to check more commonly defective parts first before replacing the control board.

Faulty Main Control Board

The main control board regulates the compressor and fan motor voltage. If the main control board fails, some components will not function properly or will not work at all. In addition, main control boards are often misdiagnosed; check more commonly defective parts before replacing the main control board.

Defective Temperature Control Board

The fan motor and compressor will not get power if the temperature control board is defective. Control boards are often misdiagnosed; check other air conditioner parts before replacing the temperature control board. If you are certain

Damaged Temperature Control Thermostat

The temperature control thermostat is a sensor that monitors the air temperature and activates a switch to provide power to the fan and compressor when the air temperature drops below a set point. If the thermostat isn’t working, the air conditioner will cool continuously or won’t cool at all.

To determine if the temperature control thermostat is defective, use a multimeter to test it for continuity. If the thermostat does not have continuity, replace it.

Faulty Thermistor

The thermistor is a sensor connected to the control board that detects the temperature of the air. The resistance value of the thermistor changes in conjunction with the air temperature. If the air temperature rises, the resistance value will decrease.

To determine if the thermistor is at fault, use a multimeter to test it for continuity. If the thermistor does not have continuity, or if the thermistor’s resistance does not change with a change in temperature, replace the thermistor.

Damaged Run Capacitor

The run capacitor is connected to the compressor with electrical leads. If the run capacitor burns out, the compressor will not run. To determine if the run capacitor is burned out, test the capacitor using a multimeter. If the capacitor does not have continuity, replace it.

How to Unlock Friedrich air conditioner

To unlock the control panel;

To lock the panel;

• Press and hold the FAN SPEED and TIMER SCHEDULE buttons for 3-seconds.
• The lock icon will appear, indicating the panel is now locked.

How to reset check filter light on Friedrich air conditioner

To reset the CHECK FILTER reminder, press the CHECK FILTER button.

How to reset your Friedrich air conditioner

To reset your Friedrich air conditioner, press the reset button while your unit is turned off and wait for 5 seconds. Then, power on your air conditioner to see if this solves your problem.

Note: Your Friedrich air conditioner’s built-in reset button is located next to where the power cord plugs into the unit.

How to set the timer on the Friedrich air conditioner

Set Hour Clock – Press Set Hr. once to see the current clock setting. Continue pressing the button until you arrive at the current time (Hour only). Minutes are not shown on display. Make sure that the A.M. / P.M. setting is correct.

• Start Timer – Press Start to view the current start time for cooling. Continue pressing the Start button until you arrive at the start time you desire. The start time for cooling will then be set.
• Stop Timer – Press the Stop button. Continue pressing the Stop button until you arrive at your desired stop time. The stop time for cooling will then be set.
• Turn timer On / Off – Press the On/Off button to activate (light on) or deactivate (light off) the timer. Once the on and off times have been selected, they will remain in memory and cycle daily until changed.

Notes: You can set the START and STOP times a minimum of one hour apart and a maximum of 23 hours apart.

If the unit is unplugged or the power is interrupted, the Set Hr. The function must be reset, or the On/Off function will not work.

How long does a Friedrich air conditioner last?

The Fredrich air conditioners can last for eight to 10 years. Some units, however, may have a shorter or longer life span, depending on how well they’re maintained. For example, some air conditioners can last up to 15 years if used sparingly and cared for properly.

Why is my Friedrich air conditioner not cooling?

If your Friedrich air conditioner is not cooling, the air filter is dirty or clogged, objects restrict airflow at the front of the unit, open cool air outlets, or freeze the cooling coils. A dirty filter is your primary suspect and can be fixed by cleaning the filter.

Dirty/Clogged Air Filter

Air conditioners rely on airflow to supply cooled air to your room. If the airflow is compromised, the air conditioner has no air to cool or send to your home.

A dirty and clogged air filter mainly compromises an AC’s airflow. Unfortunately, this also minimizes your AC’s overall efficiency and can cause other AC issues like frozen cooling coils.

How to Identify Friedrich AC Dirty/Clogged Air Filter

You’ll need to open the outer panel of your indoor unit to reveal the air filter and check if it’s covered with debris. 

How to Clean Dirty/Clogged Friedrich AC Air Filter

The Friedrich air conditioner manufacturer advises that you clean your AC’s air filter at least once a month or more often, depending on the AC’s usage and the level of dust in your environment.

Follow these steps to clean your dirty or clogged Friedrich AC air filter:

• Unplug the unit from the wall socket.
• Remove the top cover off the unit to pull out the electronic cell and pre-filter.
• Vacuum the electronic cell and pre-filter. Set them aside.
• Vacuum the interior of the unit. Remove and vacuum the carbon filter. Carbon filters lose odor absorption after approximately three to six months; remove and throw away the carbon filter if you notice any smells on the out-flowing air when it is in use.
• Wash the electronic cell in a dishwasher or carefully in a large container of hot water (150 to 170 degrees F) and mild detergent or allergen-reducing cleaner.
• Soak the cell for at least 15 minutes if you’re cleaning in a container.
• Shake the container slightly from side to side approximately every three minutes to dislodge any particles/debris.
• Rinse the pre-filter under hot running water and wash it with detergent or cleaner.
• Use grease and smoke remover for grease or smoke in/on the filter.
• Rinse the electronic cell by placing it in another large container of hot water and allowing it to soak for at least 10 minutes.
• Rinse it and the pre-filter under clean hot running water afterward to remove any remaining dirt or detergent/cleaner residue.
• Set the cell and pre-filter aside to air-dry.
• Replace the carbon filter, if necessary, while waiting for the cell and pre-filter to dry.
• Reassemble the unit after the cell/pre-filter dries completely.
• Re-position your unit in a room.
• Place the unit at least 8 inches from any wall, so the rear intake grille has adequate airflow (unblocked).

Note: If your Friedrich AC filter is worn out or damaged, replace it immediately.

Clean your Friedrich Air Cleaner filters at least once a week. If it is used in high traffic or dusty/smoky areas or continuously, check the filters daily and clean as necessary. Dirty filters can block airflow or allow too much accumulation of particles in the unit resulting in poor air purification.

Additionally, dirty filters can cause inefficient power distribution in the electronic cell reducing the charge to the collector plates and allowing particles to pass through and out of the unit without collection.

Restricted Airflow

Apart from a dirty or clogged filter, airflow into your Friedrich air conditioner may be restricted by objects in front of your cooling unit.

How to Prevent Restricted Airflow to your Friedrich AC

Ensure that furniture, blinds, curtains, or indoor plants are not in the way of the air flowing into your AC.

Wrong Thermostat Setting

The thermostat is the temperature control center of your cooling system. Your Friedrich AC thermostat has to be set on Cool Mode to blow cold air.

Depending on your Friedrich AC model, you either have a selector thermostat with buttons to set the Mode and increase/decrease the temperature or a knob that turns from Low Cool to High Cool.

The typical Friedrich AC cooling temperature setting on the thermostat is 78°F for cooling, which you can decrease to your comfort. But, if your thermostat is set too high, the AC will not cool.

How to Fix Wrong Thermostat Setting on your Friedrich AC

Press the increase/decrease button on the thermostat if that’s your model’s option to set your desired temperature. Then, for the models with a knob, turn the knob slowly from Low Cool to High Cool till you have the temperature that suits your comfort.

In both cases, the temperature has to be lower than the room temperature, or your Friedrich AC won’t be cooling.

Open Cold Air Outlets

Cold air from your Friedrich AC is meant to circulate in your room to keep you cool. But, if the air being cooled has an outlet to the outdoors, the room you intend to cool will not attain the required temperature.

Cool air outlets may be open doors and windows, open furnace floor registers, and open-air vents.

How to Fix Cold Air Outlets

When your Friedrich air conditioner is cooling, ensure that the doors, windows, and open furnace floor registers are closed. The air conditioner’s vent should also be set to a closed position.

Frozen Cooling Coils

A frozen Friedrich AC sounds odd during the hot season. But yes, your Friedrich AC can freeze up if:

• The airflow is compromised due to a dirty filter or a blocked airway.
• Dirty cooling coils.
• Disjointed or wrong-size ductwork.
• Low refrigerant levels.
• A faulty fan blower.

How to Detect Ice on Friedrich AC Cooling Coils

You can tell that your Friedrich AC has ice on the cooling coils if:

• There’s water leaking from the indoor unit.
• The outer casing of your indoor unit has sweat-like water droplets.
• You can see ice on the cooling coils when you open the front panel and remove the air filter.

How to Fix a Friedrich AC Frozen Cooling Coils

To remove ice from your Friedrich AC frozen cooling coil, leave your cooling unit switched off for some time to allow the ice to thaw.

If that would mean having you freeze instead, set your AC’s thermostat at Med Fan or High Cool to speed up the thawing process.

Friedrich Air Conditioner Not Turning On

This may be caused by power issues such as an unplugged cable or failed power supply. The circuit breaker may also be tripped, or the fuse is blown. Always check if the AC power cable is plugged in and the unit won’t turn on before assessing it for other power issues.

No Voltage to AC

A Friedrich air conditioner without voltage is not going to turn on. This could be caused by an unplugged AC cable or a power outage.

How to Fix Voltage Issues with Your Friedrich AC

Always check if your Friedrich air conditioner is plugged in before proceeding to check the unit for other issues causing it not to work. Ensure there’s no power outage in your area. If these two are not the cause for an AC not turning on, a tripped circuit breaker or blown a fuse is the next possible cause.

Tripped Circuit Breaker or Blown Fuse

Circuit breakers or fuses are control parts in a central main service panel that protects electrical appliances from current overload.

If there’s an overload, a short circuit, or a ground fault at your Friedrich AC’s circuit breaker, the circuit breaker will trip, or the fuse will blow. This means the electrical flow will shut off to protect the circuit from damage.

How to Tell if a Circuit Breaker has Tripped or a Fuse Blown

A tripped circuit breaker will have the switch that regulates the voltage going to your AC pushed down (switched off). If the entire electrical system is threatened, the main switch of the circuit breaker would be switched off. A blown fuse will have a gap in the wire or a metallic/dark smear inside the glass of the fuse.

How to Fix a Tripped Circuit Breaker or Blown Fuse

If the switch that controls the power to your Friedrich AC at the circuit breaker is pushed down, gently push it up to switch it on. Never force a circuit breaker switch up if it feels hard to turn. Instead, call a trained electrician to find the root cause of the tripped circuit breaker and do the necessary repairs.

As for a blown fuse, it needs to be replaced. Consult a reliable electrician for advice on what you should purchase or have them do the job for you. If your Friedrich AC was not working due to a blown fuse or a tripped circuit breaker, it should resume cooling with these troubleshooting/repair options.

Friedrich Air Conditioner Not Draining

If your Friedrich air conditioner is not draining, there are two issues you should check for: a blocked drain line or extremely low humidity levels. A clogged drain is most common and should be rectified by unclogging the drain to prevent reverse water flow and destructive leaks.

Blocked Condensate Drain Line

If the condensate produced by a cooling Friedrich AC is not running out from the drain pipe to the outdoors, the drain line is most likely clogged. This will eventually cause standing water in the drain line, which can overflow to the cooling unit or cause leaks.

How to Diagnose a Blocked Condensate Drain Line

If your Friedrich AC’s condensate drain line is leaking, you will notice one or more of these signs:

• A leak or standing water in the areas around the indoor cooling unit.
• A wet or moldy wall around the cooling unit.
• A musty smell in the air vents or near the unit.
• No water running out of the outdoor exit of the drain line.
• Standing water in the drain pan.
• Pieces of dirt come out of the drain line when you put a wire or thin stick into the drain line.

How to Fix a Blocked Condensate Drain

Follow these steps to unblock a dirty condensate drain line:

• Switch off the AC.
• Empty any standing water in the drain pan using a rag to soak and squeeze it into a bucket.
• Use a shop vacuum to suck up water and debris from the condensate drain.
• Use a piece of long thin wire or a plumber’s snake to remove any objects stuck in the way of the condensate.
• Once the drain line is clear, throw a bucket of warm water with a bit of vinegar and kitchen detergent to clear the drain of any debris around the pipe.
• Switch the AC back on and monitor it to see if the condensate is eventually draining.

Low Humidity Levels

Depending on your model, your Friedrich AC may send the condensate water from the base pan to the condenser coils as a cooling agent. This is a normal operation, especially on high humidity and rainy days, reducing the amount of water sent down the drain line.

But if your Friedrich AC is producing little or no condensate and, therefore, not draining, the humidity levels in the ambient may be extremely low. That means the moisture taken from the air being cooled is not enough to create moisture that’s sent out through the drain line.

Note: low humidity levels in your home are uncomfortable for you and are a damage risk for furniture and other home fittings and should, thus, be controlled.

How to Control Low Humidity Levels

The ideal humidity levels should be between 30% and 50%. You can measure that using a hygrometer or reading the humidity level on your thermostat. You’ll be uncomfortable inside your home if humidity levels are below 30%.

The best way to control humidity levels during cooling or heating is to install a humidifier. Talk to an HVAC expert about the best options.

Temporary solutions for increasing humidity levels in a home include:

• Letting in moisture from the shower/bathroom.
• Boiling/cooking with pans without lids.
• Keeping indoor houseplants.

Friedrich Air Conditioner Not Turning Off

If your Friedrich air conditioner is not turning off, it has dirty condenser coils, a faulty control board, or a short-circuited thermostat. Dirty condenser coils are the most common cause of an AC not turning off and can easily be rectified by cleaning the coils.

Dirty Condenser Coils

AC condenser coils dissipate the heat in the refrigerant as it passes through them. If the condenser coils are dirty, the heat is not dispersed, and the refrigerant can freeze in the coils, which compromises the efficiency of your AC.

An AC that is heating up due to dirty condenser coils will work harder to obtain the required temperature in your home, which is why it will stay on and not turn off in the usual 10-15 minute cycles.

How to Check if your Friedrich AC Condenser Coils are Dirty

To check if your Friedrich AC condenser coils are dirty, remove the outer casing of the outdoor unit to notice any debris and dust on the coils, then proceed to clean.

How to Clean Dirty Friedrich AC Condenser Coils

Condenser coils are a delicate part of your Friedrich AC since bent, or damaged coil fins can compromise the airflow. As such, getting a professional to do the cleaning is always advisable.

If you decide to DIY, follow these steps to clean your Friedrich AC condenser coils:

• Switch off your Friedrich AC, unplug, and wait for it to cool.
• Remove the outer casing of the outdoor unit to reach the coils.
• Using a soft brush vacuum attachment, remove debris and loose dirt from the condenser fins. Avoid any hard brushes as those could damage the fins.
• Use a low-pressure hose to spray water on the coils while paying attention not to wet any of the electrical components.
• Leave the unit open to allow the coils to dry completely.
• With the coils completely dry, put the outer casing back in place and check whether your AC resumes normal cooling cycles.

Faulty Control Board

Voltage to all parts of your AC is controlled at the main control board. If the control board malfunctions so that power flows continuously to the compressor and the fan, your AC will run non-stop and not turn off. 

How to Diagnose a Faulty Friedrich AC Control Board

The control board is often misdiagnosed. The surest way to tell if your AC’s control board has malfunctioned is by checking all the other possible causes of continuous AC running.

If you hire a pro, the expert HVAC or electrician will use a multimeter to tell if there are issues with the control board.

How to Fix a Faulty Friedrich AC Control Board

Once a trained HVAC expert has determined that your AC’s control board is faulty, it will have to be replaced.

A Shorted Thermostat

When the temperature in your home goes below the set level, the thermostat will direct the compressor and fan to start running. Once the set temperature is attained, the thermostat will signal the fan and compressor to turn off.

If your thermostat shorts due to a surge in power and cannot send signals to the compressor and fan, the AC will keep running non-stop.

How to Diagnose a Shorted Thermostat

A multimeter is used to tell electrical continuity in a thermostat. If your thermostat shows continuity continuously, then it may have shorted.

How to Fix a Shorted Thermostat

A trained electrician may repair faulty wires on a shorted thermostat. But the most likely scenario is that your AC’s shorted thermostat is replaced with a new one.

Why does my Friedrich air conditioner keep shutting off?

When the air conditioner is malfunctioning, a component within your AC unit fails. This is known as short cycling if your central air is starting up and shutting down for no discernable reason.

However, short cycling can be caused by a dirty filter, filthy coils, or extremely hot temperatures outdoors that your AC thermostat cannot match. Check the control panel for any error code that may pop up on the screen, which would determine the source of the issue.

What is Short Cycling?

Short cycling is used in HVAC when a heating or cooling cycle shuts down prematurely, and the HVAC unit turns on and off frequently. For example, air conditioning units are said to be short cycling when they turn on and off before they cool the environment to the desired temperature.

For various reasons, short cycling is problematic, as it causes higher energy bills and unwanted wear and tears on the HVAC system. Short cycling can be caused by defective parts, a dirty or poorly maintained system, or faulty components.

Below are some reasons why your AC system keeps going on and off;

1. Thermostat is Faulty or Improperly Placed

The thermostat determines when your AC shuts off. If there is a malfunction with the thermostat, then the colling cycle will shut down prematurely. A problem can cause this in the thermostat itself or an electrical problem, like bad wiring to the thermostat.

Another way that the thermostat can cause your AC to shut down suddenly is if it is improperly placed. For example, when the thermostat is placed away from windows, near an air vent, or on the shady side, it may incorrectly read that the house is cooled to the desired temperature.

2. Dirty Air Filters

Your air filters for your central AC should be changed about once a month during the warm summer months. The airflow is restricted when the air filters get dirty and choked with dust and dander. This causes the evaporator coils to freeze, which can cause the AC unit to shut down prematurely.

3. Frozen Evaporator Coils

The evaporator coil is inside your air handler, removing heat from the air inside your home. This cooled air is recirculated by the blower back through the air vents. When the evaporator coils get dirty, or if the airflow is insufficient, frost and ice can form on the coils, causing the unit to shut down suddenly. The HVAC system must work harder to defrost the evaporator coil, causing wear and tear as the unit overheats.

4. Condenser Coils are Dirty

The condenser coils are outside the home and release heat to the outside during the summer. In a central AC system, these coils are in the outside unit, usually on a concrete slab, with fan-like fins on the top of the unit. When the condenser coils are dirty and coated with dust, debris, and grime, they can struggle to perform heat exchange properly. This can cause the unit to overheat and shut down prematurely.

5. Low Refrigerant Levels

Refrigerant is a substance that runs through the coils in the AC unit and performs a heat exchange. In the warmer summer months, the refrigerant absorbs heat from inside your home, then dissipates it outside via the condenser coils. When your refrigerant line leaks, the heat exchange will struggle to function correctly. Call a licensed HVAC contractor immediately if you suspect a leaky refrigerant line.

Ignoring a leaky refrigerant line can cause damage to the most expensive components in the HVAC system if ignored. Please note that refrigerant should be self-contained in the line. There shouldn’t be a regular “topping off” of refrigerant. If the refrigerant is low, there is a leak in the like that must be fixed, or the problem will reappear.

6. Air Conditioning Unit is Oversized for Your Home

This can seem counterintuitive, but if your cooling system is sized for a much larger home than yours, it can cause short cycling. HVAC systems are built to remove a certain amount of heat from a certain amount of indoor space. When you have an oversized unit, it cools the home much quicker than it should, causing it to shut down quickly.

However, your home heats up again quickly, causing short cycles where the AC runs for ten to fifteen minutes, shuts down, then starts up again. Air conditioners are more efficient on energy when they keep the room at an even temperature.

7. Faulty Run Capacitor

Your AC system’s run capacitor has an important role. The run capacitor provides enough electrical current to turn your colling unit on and enough power to keep the air conditioner running.

Power may only sporadically run to the air conditioning unit when the run capacitor fails. This causes the AC system to turn on and off quickly. Another sign of a failing run capacitor is that the AC system is not blowing cold air.

8. Your AC System has Electrical Problems

A common reason for a short cycling AC system is electrical problems. This may be caused by a bad connection, a broken thermostat, a faulty circuit board, or a condenser or compressor not receiving power properly. Call a licensed HVAC contractor to diagnose and repair the electrical issue properly.

How to Fix a Short Cycling Air Conditioning Unit

If you have gone through the checklist above, and none of the things you can do easily fix the problem, contact a professional air conditioning contractor.

What are the Effects of a Short Cycling Air Conditioner?

Air conditioning systems can short cycle for weeks or months before the issue is fully detected. Perhaps you notice that the AC system is not blowing cold air, or you notice a pattern of the air conditioner shutting off after ten to fifteen minutes, and you need to do something to fix the situation.

While the AC system is short cycling, these cumulative effects are happening: Increased humidity in your home. Your air conditioning unit removes humidity as well as heat from the inside of your home. When the AC system is short cycling, the humidity in the air remains inside. This can exacerbate condensation in humid local climates—higher energy bills.

When your central air conditioner must work harder, it raises your electric bill. A short cycling heating and cooling system use more energy than a perfectly functioning system, with less efficiency. Wear and tear on your central AC system. Air conditioning units have a shelf life of about fifteen to twenty years when the unit is short cycling for an extended period, which wears down the compressor and condenser components.

Why is my Friedrich air conditioner making loud noises?

Air conditioners normally have a low, quiet humming or whirring noise due to the fan motor. However, loud noises indicate problems with your Friedrich AC. For instance, a loud, banging, or rattling noise may indicate a bent fan blade or debris rattling around your unit.

A squealing noise indicates a compressor problem. Loud whirring means the fan motor is faulty. Determine the noise from your air conditioner, and have our technicians check your unit.

How to change Friedrich air conditioner filter

Follow these steps to change the air conditioner filter;

• Remove the front panel.
• Using the handles, pull the panel out until it is released from the two retaining snaps. Place the cover aside carefully.
• Remove the filter by pulling it from the handles and releasing it from the slots on the frame.
• Then replace the filter by inserting each tab in its respective slot.
• Replace the front panel by positioning one of the sides in the snaps of the handle first and then the other side. Ensure that both snaps are correctly aligned and that the logo is in the right position.

How to install/replace Friedrich Kuhl the carbon filter

The Friedrich Premium Carbon Filter lets your air conditioner absorb odors and reduces ozone and volatile organic compounds (VOCs). Follow the steps below to install or replace your air conditioner’s filter;

Before You Start

For safety, before replacing your filter, you’ll first want to unplug the window air conditioner.

Step 1: Open the Front Cover

Open the front cover by grasping both sides of the Kuhl’s door, pulling it down, and towards you to access the existing filter.

Note:  Filter replacement instructions are also located inside the door.

Step 2: Remove the Filter

Remove the existing filter by gently lifting and pulling the bottom of the filter out towards you. Take care to pull the filter out delicately, so it’s not damaged.

Step 3: Remove the Filter Grip

Before inserting a new Friedrich Kuhl Carbon Filter, you must first open the filter so a new carbon filter can be placed inside. To open, grip from the side and slide the filter grip off the bottom. It may take a little force to slide the grip, but it should slide off relatively easily.

Step 4: Open the Filter

Open the filter and, if necessary, clean it with a mild soap solution.

Note:  After cleaning, you’ll need to let the filter air dry before installing the new carbon filter. This will ensure the filter works in tip-top shape.

Step 5: Place the New Carbon Filter

Place the new carbon filter inside the filter housing by laying the carbon filter in the cassette and closing it. When closing, ensure that the filter closes completely and latches in place.

Step 6: Replace the Filter Grip

Seal the filter by sliding the filter grip back onto the filter.

Note:  If the tab on the frame prevents the grip from sliding onto the filter, the grip is not properly positioned. Remove the grip and slide it in the other direction. Forcing the grip into place can damage the filter.

Step 7: Reinstall the Filter

Align the edges of the filter with the guide tabs. Slide the filter halfway into the unit, then tip the top of the filter towards you, and gently slide the bottom into place. Be careful not to pinch your fingers as you slide the filter back.

Step 8: Close the Front Cover

Close the front cover and plug the Kuhl back in to operate as normal. That’s it! You’ve just installed a new premium carbon filter from Friedrich. So go ahead and set your air conditioner to that perfect setting and get back to having a cooler indoor space and a cleaner one.

How to set up Wi-Fi on Friedrich uni fit air conditioner

The CnCT Menu is used to turn on the Wi-Fi connection. Press the menu button to activate Wi-Fi.

To set up Wi-Fi, follow these Wi-Fi setup instructions;

1.         Write down the following information before beginning this process

(If you do not know this information, you can check your router or contact your internet provider)

a.         WI-FI Network Name (SSID)        

b.         WI-FI Network Security Type (Open, WEP, WPA, wpa2)        

c.         WI-FI Network Password

2.         Using a mobile device such as a smartphone or laptop, navigate to www.FriedrichConnect.com.

Note:  If you do not have an account with FriedrichConnect, you will be given the option to create a new account.

3.         Sign in using your username and password.

4.         Click the “Add Device” button.

5.         Select the time zone the device is located in and click the “Next” button.

6.         To start the setup process, click the Control Panel’s menu button.

Note:  If the Display is not illuminated, you need to click the menu button to illuminate the display and then click it again to start the setup process.

7.         Using the up and down arrows, navigate to the CnCT screen.

8.         Click the menu button. This will begin the setup process for your Friedrich Connect-enabled device.

Note:  When the setup process starts, the WI-FI symbol will begin to flash. This indicates the A/C unit is trying to connect to your Wi-Fi network

Note:  Once the setup process has been started, you will have five minutes to complete the setup. If the setup can not be completed in five minutes, the system will rest, and you will need to restart the process.

9.         After the Wi-Fi symbol blinks, click the “Next” button on your mobile device.

Note:  If the Wi-Fi setup is not completed on the first attempt, you may need to reset the Air Conditioning control unit. To accomplish this, turn the unit off, and unplug the Air Conditioning unit for a minimum of 15 seconds. Then, plug the unit back in and start the setup process over.

10.       Go to your mobile device’s Wi-Fi settings and connect to the “FriedrichConnect_xxxx” network. (XXXX is the network name of the Friedrich unit)

11.       Go back to the Friedrich instructions on your mobile device and click next.

12.       A screen will appear asking you to enter your Wi-Fi credentials.

13.       Enter the information as you recorded it at the beginning of the process.

Note:  Your device may auto-populate the fields incorrectly.

Note:  Be sure to enter the WIFI SSID, Network Security Type, and Wi-Fi network password exactly as you recorded them.

Note:  These fields are case-sensitive.

 14.      Click next.

Note:  You will receive a pop-up box stating, “Credentials successfully saved.

Please connect back to your Wi-Fi network and click “Next.”

Note:  You will receive a message (Waiting for network connection).

15.       Go back to the Wi-Fi settings on your mobile device and connect back to your Wi-Fi network.

16.       Go back to the Friedrich instructions on your mobile device and click next.

Note:  You will receive a message stating, “Looking for the recently added device. It will appear in the list ready. “Please wait. This may take up to 3 minutes”.

Note:  Please wait and do not close out the box that appears.

If the box is closed before you get a successful message and you do not see your device (Friedrich a/c under my devices)

then you will have to restart the setup process again due to the unit not being linked to your Friedrich Connect account.

Note:  It will connect to the Friedrich unit before the 3-minute mark in most cases; however, it may take up to 3 minutes to be connected. Once it is connected, you will receive a successfully connected box.

Note:  Your Home Screen Wi-Fi symbol will stop flashing and will show steady.

Note:  A GREEN symbol will appear under the “Status” details and the name of your Friedrich unit, which will appear with a number. For example: (62601032R01184660025)

Wi-Fi Troubleshooting Tips

If you received this error message

“Error in association process: Request has been terminated. Possible causes: the network is offline, Origin is not allowed by Access-Control-Allow-Origin, the page is being unloaded, etc.”

This means your Wi-Fi (internet connection) has gone off online.

• Check your Wi-Fi signal strength, reconnect service to your router or restart your router depending on your internet services.
• Reset your Air Conditioning unit by turning off the power and then unplugging the unit for a minimum of 5 seconds.
• Log back into your account and restart the setup process.

If you are on the last step where it states

“Looking for the recently added device. It will appear in the list when ready. Please wait. This may take up to 3 minutes. Then a message below states, “Unable to find the device. Please double check the WI-FI SSID and password and try again”.

• You entered the wrong WI-FI network name (SSID) or password.
• Reset your Air Conditioning unit by turning off the power and then unplugging the unit for a minimum of 5 seconds.
• Log back into your account and restart the setup process.

Friedrich air conditioner remote controls guide

START / STOP: – Press this button to turn on the unit. Press this button again to turn off the unit.

Down Arrow: – Press this button to decrease the set temperature. Hold it down for 2 seconds to decrease the set temperature rapidly. In AUTO mode, the set temperature is not adjustable.

Up Arrow: –Press this button to increase the set temperature. Hold it down for 2 seconds to rapidly increase the set temperature. In AUTO mode, the set temperature is not adjustable.

FAN: – AUTO This button is used for setting Fan Speed in the sequence that goes from AUTO, Low, Medium, and High speed, then back to Auto.

MODE: – Each time you press this button, a mode is selected in a sequence that goes from AUTO, COOL, DRY, FAN, and HEAT. It is only available for models with heating functions.

After energization, AUTO mode defaults, in AUTO mode, the set temperature will not be displayed on the LCD, and the unit will automatically select the suitable operation mode following the room temperature to make the indoor room comfortable.

SENSOR (SAVE): – Press this button to turn on, and it automatically adjusts, maintaining that room ambient until pressed again, which cancels the SENSOR(SAVE).

CLOCK: – Pressing the CLOCK button, present time. Holding down either button above 2 seconds increases or decreases the time by 1 minute every 0.5 seconds and then by 10 minutes every 0.5 seconds. During blinking after setting, press the CLOCK button again to confirm the setting, and then it will be constantly displayed

TIMER ON:- Press this button to initiate the auto-ON timer. To cancel the auto-timer program, simply press this button again. After pressing this button,       disappears and “ON “blinks. 00:00 is displayed for ON time setting.

Within 5 seconds, press + or – button to adjust the time value. Every press of either button changes the time setting by 1 minute. Holding down either button rapidly changes the time setting by 1 minute and then 10 minutes. Within 5 seconds after setting, press TIMER ON button to confirm.

 AIR SWEEP:- Press this button to set up & down swing angle. This remote controller is universal. If any command is sent out, the unit will carry out the command and guide the louver swings.

EXTEND(DRY): – Pressing EXTEND button in COOL or DRY Mode, the fan icon is displayed and the indoor fan will continue operation for 10 min utes in order to dry the indoor unit even though you have turned off the unit.

After energization, EXTEND OFF is defaulted. EXTEND is not available in AUTO, FAN or HEAT Mode.

TEMP:- By pressing this button you can display the indoor setting temperature or indoor ambient temperature.

When the indoor unit is first powered on it will display the setting temperature, if the temperature’s display status is changed from other status to the ambient temperature, 5s later or within 5s, it receives other remote-control signal that will return to display the setting temperature.

If the users haven’t set up the temperature displaying status, that will display the setting temperature.(This function is not applicable for some models).

TIMER OFF:- Press this button to initiate the auto-off timer. To cancel the auto-timer program, simply press the button again. TIMER OFF setting is the same as TIMER ON.

TURBO: – Press this button to activate / deactivate the Turbo function which enables the unit to reach the pre-set temperature in the shortest time. In COOL Mode, the unit will blow strong cooling air at super high fan speed. In HEAT mode, the unit will blow strong heating air at super high fan speed. (This function is not applicable for some models).

SLEEP: – Press this button to go into the SLEEP operation mode. Press it again to cancel this function. This function is available in COOL or DRY Mode to maintain the most comfortable temperature for you.

LIGHT: – Press LIGHT button to turn on the display’s light and press this button again to turn off the display’s light. If the light is turned on, the bulb is displayed. If the light is turned off, it disappears.

Combination of “+” and “-” buttons: About lock

Press “+ ” and “- ” buttons simultaneously to lock or unlock the keypad. If the remote controller is locked,           is displayed. In this case, pressing any button,  blinks three times.

Combination of “MODE” and “-” buttons:- Allows you to toggle between Fahrenheit and Celsius. When the unit is OFF,press “MODE” and “- ” buttons simultaneously to switch between℃ and ℉.

Replacement of Batteries

1.Remove the battery cover plate from the rear of the remote controller.

2.Take out the old batteries.

3.         Insert two new AAA1.5V dry batteries, and pay attention to the polarity (+/-).

4.         Reinstall the battery cover plate

Notes:

●          When replacing the batteries, do not use old or different types of batteries. It may cause malfunction.

●          If the remote controller is not used for a long time,  remove batteries to prevent batteries from leaking.

●          Remote should be kept 3 feet away from the TV set or stereos.

●          If the remote controller does not operate normally, remove batteries and reinsert them after 30 seconds. If abnormal operation continues, replace the batteries.

How to program a Friedrich air conditioner app

The Friedrich app can be found in the Apple iTunes or Google Play stores. Or you can download it by scanning the QR code in your user manual.

Note:  The FriedrichGo App is supported on 2.4 GHz Wi-Fi Channels only. Please be sure your connection is using a Wi-Fi channel broadcasting in 2.4GHZ

After downloading the FriedrichGo App, you will find the “FriedrichGo” icon on your phone/ mobile device. Home screen.

How to sign up for your user account

Once you download the App, you will need to create an account. Click the “Sign up” button to begin the registration process.

You can register with your email address or with a mobile phone number.

Once you have created an account, click the “Sign In” button to sign in to your account using the email or mobile phone number that was used for registration.

You can update your home name and select the rooms.

Reset password

Follow these below steps to retrieve a forgotten password:

1.         Press the “Forgot password” button to replace it.

2.         Type in the registered phone number or email address and press the “Next” button to continue.

3.         You will receive a verification code to continue. Type in the code received and set a new password. Press “Confirm” to finish.

Follow the directions below to add an AC to your FriedrichGo account. This will allow you to control your units from your Mobile App:

4. Press the “+” and click the “Floating Air Pro/Premier” to connect.

Connecting your AC to a wireless network can be completed using AP (Access Point) Mode. (Reminder-The FriedrichGo App only works on 2.4 GHZ networks)

Setup Modes:

• “77” should show on the page as illustrated below. Press “Next Step” to continue.
• Press “Left-Right Swing” on the remote controller six times a row. Once the display on the indoor unit shows “77” and five short beeps are heard, Continue to the Next Step.
• Select the Wi-Fi network you are trying to connect to, type in the password, and press “Confirm” to continue.
• 0pen your mobile device settings to get to Wi-Fi connections.
• ” Friedrich-XXXX” should show as an available network connection option.
• Connect to the Friedrich-xxxx network.
• After connecting to the “Friedrich -xxxx” network using the AC unit’s Wi-Fi adapter, return to the Friedrich Go App to resume setup.
• The AC unit will automatically begin installing/syncing on the mobile device.
• When the connection is complete, the FriedrichGo App on your mobile device will show the unit connected with a check mark as illustrated.
• If the setup connection fails, the App will display a warning. Press “Got it” to try the connection again or “View help.”
• Once connected, you are ready to begin controlling your AC unit from your mobile device.

Air Conditioner Control

• Tapping the Air Conditioners name to enter the control mode. For example, tap the ON/OFF button for power and then remotely control your Air Conditioner.
• Adjusting settings for operation mode, Fan, Dry, Heat, or Cool. Tap the “Mode” button and choose the Mode.
• For Fan mode, press the “Fan” button and choose the speed: Quiet, Low, Med, High, Ultra High, or Auto.
• Unit Modes, select “Functions.” This will open the modes selections.

Notes:

1. Dry Mode is preset to 4F/2C lower than room temperature, low fan speed and cannot be changed.
2. Heat mode only applies to Heat Pump units.
3. Fan mode is preset to 79F/26C and cannot be adjusted. –
4. Auto mode is preset at 79F/26C for cooling or 72F/22C for heating and cannot be adjusted.
5. Cool Mode, Temperature settings can be adjusted to the desired temperature.
6. Tap the three-dot icon on the App’s upper-right corner for more options. Here you can Modify device name, Device location, Shared devices, Device info, Feedback, Check for firmware updates, Remove a device or Restore defaults.

User profile

You can manage your personal information. The user profile includes:

a.         Account information

b.         Scan QR code

c.         The message center will display any messages sent to the App.

• Pattern unlock: Tap “Gesture unlock” under the personal center. Here you can set up an unlock pattern. Once enabled, you will have to use the pattern to unlock App.

Note:  The first registered mobile device is the main control, and other devices can only be shared through the primary device. Shared accounts need to be setup for the same country.

Friedrich Go App Setup Troubleshooting

Air Conditioner set up unsuccessful     

• Check that the Wi-Fi address and password are correct for the network you are trying to connect to.
• Check the air conditioner under configuration status.
• Check to ensure no firewalls or other restrictions prevent set up on the wireless network.
• Check that the router is working properly.
• Ensure the air conditioner, router, and mobile device are all within signal range to connect.
• Check to see if the router is blocking the FriedrichGo App from connecting

Note:  The Friedrich Go App is only supported on 2.4 GHZ Wi-Fi Channels. Please be sure your connection is using a Wi-Fi channel broadcasting in 2.4GHz.

Mobile Device not controlling Air Conditioner.   

This means that the air conditioner has been reset, and the mobile device has lost the control permissions. Therefore, reconnection to the WI-Fl network is required. If this does not fix the issue. Please delete the selected air conditioner in the App and reinstall it.

How to empty a Friedrich portable air conditioner

As the unit works to cool and dehumidify the room, it collects excess moisture. While most of the water does evaporate, some may remain in the unit. If an environment is extremely humid, the AC will not be able to exhaust the water as quickly as it collects water. In this situation, water will collect in an internal water reservoir, and you must drain the water for the unit to work properly.

Once the reservoir is full, it will automatically shut off to prevent overflowing. Your unit will indicate when you have to drain water, often with an error message, alarm, or indicator light. You must drain the water before the unit can work.

There are several ways to drain an AC unit;

Drain It in a Pan

Before you begin, unplug the unit and disconnect all power. Next, place a pan directly under the drain port in the back of your unit. Remove the plug and allow the unit to drain. Once you have removed the plug, water will flow freely. Once the unit has completed draining, replace the drain plug, and plug the unit back into the socket.

Drain It in a Sink or Bathtub

Once you’ve unplugged your unit, carefully carry it to a sink or bathtub. To avoid leaking, move slowly, keeping it level at all times. Note that your unit surface must sit on a flat surface. Once situated, remove the drain plug and allow the unit to drain. When the unit has finished draining, replace the drain plug, return the unit to its proper location, and plug it back in.

Use a Hose

Not all AC units have a hose option, so check the manual before you choose this method. Drain hoses can remain attached to the unit and rely on gravity to drain water, meaning the hose must go downhill. Use a drain hose when the AC is in a location with a floor drain, such as a basement.

Before you begin, confirm that the hose fits securely over the drain port with a water-tight fit. You may be able to use a standard garden hose, but if it doesn’t fit properly, you can purchase an appropriate hose from a hardware store. Then, attach your hose to the unit for continual drainage.

Use a Condensate Pump

Condensate pumps also remain plugged into the AC unit and can drain water without relying on gravity. The pump has two hoses, one connected to the AC unit and the other to the pump with an open end to drain the water.

You can place the drainage end of the hose outside a window. A condensate pump will automatically turn on once a certain level of water has collected inside your AC unit. Likewise, it will turn off once it has drained most of the water.

Friedrich air conditioner remote not working

If your Friedrich air conditioner remote control is not working, the batteries may be dead, the +ve and –ve poles may be misplaced, the sensor distance from the AC may be too long, or the remote control and thermostat sensors may be defective. Dead batteries are a more common cause, easily solved with new ones.

First, try replacing the batteries in the remote control. If installing fresh batteries doesn’t solve the problem, and you can still operate the air conditioner manually, the remote control might be defective. If you think the remote control is defective, replace it.

Dead or Wrongly-placed Remote Control Batteries

Your AC remote control uses 1.5v AAA batteries. Once these are discharged (dead) or the +ve and –ve poles are wrongly placed in the battery case, the remote will not be charged and will, thus, not work.

How to Diagnose Dead or Wrongly-placed Remote Control Batteries

Use a tester to check if your Friedrich AC remote control batteries are still charged. As a rule, a 1.3v for AAA-type batteries is considered dead.

Check to see if the +ve and –ve poles are placed on the corresponding charges in the battery case.

How to Fix Dead or Wrongly-placed Remote Control Batteries

• Replace AAA remote control batteries with a 1.3v charge or less with fully charged batteries (1.5v).
• Open and correct any wrongly placed AAA batteries in your remote control by following these steps:
• Notice the Arrow on the rear side of the remote control that indicates how you should open the remote and push the cover in the indicated direction to open the remote control battery compartment.
• Insert the 1.5v AAA batteries, making sure the –ve poles of both batteries go to the side that shows negative charge (usually has a metal spring) and the +ve poles to the side that is marked positive.
• Slide the battery compartment cover back so it clicks back to its original position.

Long Limit Remote Sensor Distance from AC

An AC remote control can operate within a certain limit remote sensor distance (around 20ft). If you are too far from the AC, your Friedrich AC remote control commands will not be delivered to your AC. The limited remote control distance may also be affected by objects in front of your AC, such as furniture.

How to Fix Long Limit Remote Sensor Distance from AC

Depending on the case:

Move closer to your Friedrich AC when sending commands to your cooling unit using the remote control.

Remove any obstructing furniture or other objects from the front of your AC to clear the path of the remote control sensor.

Defective Remote Control

If the batteries in your remote control are still charged, or you’ve replaced them, and the remote control still won’t work, the remote control could be defective.

How to Diagnose a Defective Remote Control

• Check the following to tell if your Friedrich AC remote control is defective:
• Check if the sensor LED at the tip of the remote control lights when commands are pressed. If not, the sensor may be detached from the internal parts of the remote and, therefore, dead and unable to send commands to your AC.
• Operate the AC commands manually to see if they are affected. If that works, your remote control is faulty.

How to Fix a Defective Remote Control

If the wire connecting the LED sensor to the rest of the remote control internal parts are detached, it could be repaired and still function. AC remote controls are not a pricey part of your cooling system. As such, it’s always best to replace a faulty one.

Faulty main control board

The main control board has an infrared receiver that receives signals from the remote. If the infrared receiver is not working, the remote control will not be able to communicate with the control board. If you suspect the main control board is defective, replace it.

Defective Thermostat Sensor

Your Friedrich AC remote control communicates with a sensor in the thermostat to effect commands. If the thermostat sensor is defective instead of the remote control, the remote control commands won’t be delivered to your AC.

How to Diagnose a Defective Thermostat Sensor

• Operate the AC commands manually to see if they work. For example, if the remote control sensor LED lights but the AC commands are not affected when pressed manually, the thermostat sensor is most likely defective.
• Check the thermostat sensor close to the cooling coils to see if the wire is broken or out of position.

How to Fix a Defective Thermostat Sensor

If you check the thermostat sensor and the wire appears broken or bent out of position, place it back in its position or call an expert HVAC to repair/replace a broken sensor wire as the case may require.

How to clean a Friedrich wall air conditioner

Before commencing the cleaning process, gather the tools you will need.

Items needed;

• Vacuum
• A soft brush
• Soap/mild detergent
• AC fin comb
• Antifungal cleaning spray,
• Spray the bottle before opening up your AC unit. You can also use
• Rubber gloves
• Face mask
• Flashlight or headlamp

Ensure all power sources are disconnected from your AC unit to ensure safety. The unit can also be isolated by turning off the electricity to the room needing cleaning via a circuit breaker on the circuit panel. Make sure to unplug the unit carefully.

Clean Your AC’s Outdoor Unit

You may want to look at the area around the part of the unit that is outside your house. The area near the unit should be free of grass, leaves, and trash.

Wipe the cabinet’s exterior with a damp cloth. Next, clean any hard-to-clean dirt and dust with a cleaning solution such as soapy water.

Once you’ve found the fan blades, open up the unit. Wipe the blades gently with a damp cloth.

Let dry and set aside.

If your fins are bent, you can straighten them with a fin comb. Using this brush, you can clean the fins precisely because it has soft bristles.

Then it would be best if you gently vacuumed the remainder of the interior of your unit to remove any dust or dirt that has settled there.

Last but not least, carefully reassemble the unit afterward.

Clean the Indoor Unit of Your Air Conditioner

For the indoor part of your Mitsubishi inverter ac, start by wiping the surface with a damp cloth. Once you’ve done that, open the unit’s front panel with two air filters hidden behind it. Gently wash the air filters with soapy water after removing them. Using a clean, dry cloth or letting your filter air dry will remove all the moisture.

Clean your evaporator coils with water and mild detergent if they have accumulated a lot of gunk. Spray the mixture on your unit’s coils after mixing it in a spray bottle. To loosen the debris, soak it for a few minutes. You can also use coil cleaners without rinsing, which is extremely easy and effective.

Unplug the hose from your indoor to the outdoor unit to flush out your drain line. Before reconnecting the hose, let it air dry for an hour first. Once that’s done, reconnect the inside of the unit.

How to clean a Friedrich window air conditioner

1. Unplug the Unit From the Wall to Clean the Window Air Conditioner Without Removing It

You will be touching different parts of the air conditioner using a spray bottle and don’t want to get electrocuted.

2. Take Off the Grill of the Air Conditioner Unit and Take Out the Filter

Filters should be changed every 1 to 3 months in a large HVAC unit if a smoker is in the home. In a small unit, you want to check it every 30 days to make sure it is not jammed or full of dirt.

You may be able to let it soak in the bucket of soapy water and then let it air dry. On the other hand, it may be time for a replacement. If you need to replace it, refer to the manual for the correct size and be sure you have the model number. There are various sizes and types, and you need to get the correct one.

Also, remember the air filter keeps the air clean, so you want it as clean as possible. It may not need to be changed that much in a small window unit, but it is always a good idea to check. Some air conditioner units have a filter rest button that will also let you know when it is time to replace the filter.

3. Take the Case Off the Air Conditioning Unit

You can use a screwdriver to take the case off. This will allow you to see the condensation drain and other removable parts like the drain pan. You can soak them in warm soapy water to get them clean. It is important to clean the drain pan, so mold does not start growing from the water sitting in the pan.

4. Vacuum and Spray the Inside Parts to Clean the Window Air Conditioner Without Removing It

To clean the window air conditioner without removing it, use the vacuum with the soft brush attachment, and carefully vacuum out any dust balls or other stuff you see in the unit. Then, mix your water and two drops of dish detergent.

Next, spray this inside the machine and wipe the areas down. Make sure to pay attention to the fins too. Also, you can use a fin comb to clean the fins area and ensure they are straight.

5. Clean the Condenser Coils

The unit’s backside has a covering that you can also take off. This covering protects the unit from weather elements but does need cleaning. Underneath the covering is the condenser coils.

Spraying the concoction of water and detergent can clean them. This will allow the grime to run off. Some people use a hose to spray it, but it is better to use detergent to clean it more effectively. Once you do that, let this area dry.

6. Reassemble the Air Conditioner Unit

When everything is dry on the inside, put the parts back on. If you are unsure how it goes together, consult the owner’s manual. Making sure everything is dry inside is important, so you don’t have mold growing. 

How to maintain a Friedrich wall air conditioner

Maintaining your air conditioner improves efficiency, reduces energy consumption, and prevents costly repairs and a mid-summer meltdown.

Do the following to maintain your wall air conditioner;

1. Check for insect/animal nests.

If you’ve left your air conditioner uncovered in your window or wall over the winter, you’ll need to check for wasp and bees’ nests inside the unit. They love to nest there.AC air conditioner air filter material

2. Clean the air filter.

The air filter is easily accessible in most models by removing the front panel. Take the filter out and clean it gently with warm water and dish soap or white vinegar. Let the filter air dry completely before reinstalling it.

These should be cleaned once per month during the cooling season. If you have pets or allergies consider cleaning it more frequently. If the filter is damaged, it should be replaced. If your unit has a foam filter, you can purchase replacement electrostatic filter material and cut it to fit your model perfectly.

3. Clean the condenser coils.

Over time, dust and dirt will build up on the inside of an air conditioner’s condenser coils. This build-up will require your AC to work harder to remove heat, causing it to consume more energy, costing you more money to run.

Before the start of every cooling season, clean the coils within the air conditioner. You’ll need to completely remove the air conditioner cabinet to access the coils. They can be cleaned by blowing compressed air at them or by using a soft bristle brush and a spray bottle of household cleaner to wipe the dirt off.

Take great care in removing the dirt. If you accidentally bend or dent the aluminum coil fins, use a handy fin comb to straighten out the fins.

It is also important to remove dirt or lint build-up at the bottom of the air conditioner so the condensate water will be picked up by the condensing fan blade slinger properly.

4. Clean the water pan.

To prevent mold growth and a musty odor in the air, use warm water, dish detergent, or white vinegar to clean the pan at the unit’s base once or twice per cooling season.

5. Inspect cooling coils for frost or ice build-up.

If the temperature outside the room where the air conditioner is placed becomes cool (approximately 60 degrees Fahrenheit or 15 degrees Celsius or lower), check the coils on the front of the air conditioner for icing. If the coils are icing up, turn off the air conditioner until the outdoor temperature rises above 60 degrees Fahrenheit or 15 degrees Celsius.

6. Check the remote control.

You may need to replace the batteries in your unit’s remote control. Likewise, if you replace the batteries and the remote control fails to function, you should replace the remote control.

Friedrich air conditioner not blowing air

If your Friedrich air conditioner is not blowing air, it has a dirty air filter or condenser coils, blocked return air ducts, a high thermostat set point, is undersized, or the AC has entered the defrosting Mode in the heating season. A dirty filter is the most common and should be cleaned regularly.

Friedrich AC Defrosting Mode

Your Friedrich AC will defrost Mode if the outdoor unit freezes during extremely low temperatures.

This is not a malfunction, but the AC will not be blowing air when it happens since the fan is turned off automatically.

What to do When your AC is in Defrosting Mode and not Blowing Air

Your Friedrich AC will defrost Mode for only 8-10 minutes. As such, you only need to wait for it to complete the defrost cycle and turn back to the heating process automatically. Your AC should then start blowing air.

The Return Air Ducts are Blocked

Return air ducts are rectangular or square vent grates around your home. Their function is to return the air pumped out from the registers to your home back to the AC so that it can be cooled and recirculated again to the home.

If the return ducts are blocked, the efficiency of your AC is reduced as little air is returned to the AC, which explains why your AC will not be blowing air.

How to Fix Blocked Return Air Ducts

Clean the blocked return air ducts to remove debris and dust build-up. The best preventative measure is to have the return air ducts cleaned periodically during the annual professional maintenance cleaning.

High Thermostat SetPoint

If your Friedrich air conditioner is set above room temperature, it will not be blowing cold air. And if it’s a reverse cycle model, it will blow hot air.

How to Fix High Thermostat Settings on your Friedrich AC

Adjust the thermostat temperature set point to a cooler degree by checking the room temperature and lowering the current thermostat reading a degree at a time. The AC should start blowing cold air after 3-5 minutes.

Dirty Condenser Coils

Condenser coils circulate the refrigerant that works to remove the heat from the air during the cooling process. If the condenser coils are dirty, the heat will not be dissipated, the air will stay warm longer than it should, and the overall efficiency of your AC will be reduced, limiting the amount of cooled air blown into your home.

How to Diagnose Dirty Friedrich AC Condenser Coils

To check if your Friedrich AC condenser coils are dirty, remove the outer cover of the outdoor unit and notice any dust and debris build-up on and between the fins.

How to Clean Dirty Friedrich AC Condenser Coils

Follow these steps to clean dirty Friedrich AC condenser coils:

• Switch off your Friedrich AC.
• Once the AC is cooled, remove the outer casing of the outdoor unit to reveal the coils.
• Use a soft brush vacuum attachment to rid the coils of debris and loose dirt.
• Spray the coils with water using a low-pressure hose, ensuring you do not send any water to the electrical components.
• Allow the coils to dry completely before replacing the outer casing.
• Replace the outer casing and restart the AC to see if it blows air as it should.

Note:  We recommend that you hire the services of an HVAC technician to clean dirty Friedrich AC condenser coils. An expert will take care of the delicate fins and protect the electrical parts from any form of damage.

Dirty Air Filter

A dirty Friedrich AC air filter will inhibit airflow. Especially if it’s badly or completely clogged with dirt, the air filter will not let in any air, and hardly any cool air will blow from your AC.

How to Check if your Friedrich AC Air Filter is Dirty

Open the outer casing of the indoor unit, and you’ll immediately see the air filter. Unfortunately, a dirty and clogged air filter will barely let you see through it and will instead be covered with debris.

How to Clean Dirty/Clogged Friedrich AC Air Filter

Follow these steps to clean your dirty or clogged Friedrich AC air filter:

• Turn off your Friedrich AC.
• Pull the overhangs on both sides of your indoor unit to open the front panel.
• Lift the filter from the center, so the locking hood is unfastened, and pull the filter towards you to take it out. Do not touch any of the metal parts as they are sharp and could cause cuts.
• Pass a vacuum cleaner to get rid of the larger dirt particles on the filter, and then use lukewarm water with a bit of detergent to clean the filter. The warmth of the water should not exceed 113ºF.
• Shake off the excess water gently and leave it to dry completely.
• Put the filter back into the AC and ensure it clicks back into place.
• Close the front panel and resume running the AC.

Undersized Air Conditioner

If the size of your Friedrich AC in BTUs is too small for the energy load requirements of the space being cooled, the air from your AC will not be felt, which is why it will feel like the AC is not blowing air.

How to Tell if your Friedrich AC is Undersized

Follow these steps to make out if your Friedrich AC is undersized for the space requirements:

• Check how many BTUs your Friedrich AC is rated for. If not indicated on the unit, check your Friedrich AC model’s Installation and Operation Manual.
• Calculate the size of the space being cooled in square feet by multiplying its length and width.
• Check the Energy Star Air Conditioner Buying Guide to see if your AC size in BTUs corresponds to the recommended space size in square feet

What to do if your Friedrich AC is Undersized for the Cooling Space

If your Friedrich AC is too small for the space being cooled, consider replacing your cooling unit with a bigger one. This will not only provide the required temperature, but it will also save you money on energy bills.

How to set the timer on the Friedrich air conditioner

To set the Time Function;

• Tap “Timer,” and the App will enter the timer setting screen.
• The display will show the schedules that were previously set.
• You can press to edit or add new timers. (Note: Timer is 24hr clock).
• Click the “ON” or “OFF” button to set the timer ON or OFF.
• After you’re finished setting the timer, click the button to Cancel or Save.

Note:  You can set the: Hour, Minute, Operate Mode, and Operate Fan Speed. You can also set a weekly timer.

Friedrich air conditioner control panel/power buttons not working

If your Friedrich air conditioner buttons are not working, the AC has wrong thermostat settings, or a faulty control panel. Wrong thermostat settings are a common cause you can easily resolve by changing to the correct settings.

Wrong Friedrich AC Thermostat Settings

Your Friedrich AC has several thermostat Modes depending on the model. The standard modes are AUTO, COOL, DRY, FAN, and HEAT.

Some of your AC buttons do not work in all the modes. For example, your AC must be set to the COOL Mode to use the increase (+) and decrease (-) buttons to raise or reduce the cooling temperature. If it is set on AUTO or FAN mode, you will not be able to use these buttons.

How to Fix Wrong Friedrich AC Thermostat Settings

Ensure your Friedrich AC thermostat is set on the COOL Mode before using the increase (+) or Decrease (-) buttons to set your desired cooling temperature.

A Faulty Friedrich AC Control Panel

If your Friedrich AC control panel is faulty due to voltage or other internal issues, the buttons on the remote control will not be activated.

How to Fix a Faulty Friedrich AC Control Panel

Try resetting your Friedrich AC buttons by switching off the power and unplugging the AC power cable. Alternatively, you can turn off the switch at the circuit breaker switch that supplies power to your AC, then leave it off for a minute before turning it on and testing whether the AC buttons resume function.

If your Friedrich AC buttons do not work after resetting the AC, contact a Friedrich AC expert for professional help.

Friedrich AC Error Code List

Below are the various Friedrich air conditioner error codes and their meanings;

• C5       Jumper Cap Malfunction Protection
• E1       High-Pressure System Protection
• E2       Anti Freezing Protection
• E4       High Discharge Temperature Protection of Compressor
• E5       Overcurrent Protection
• E6       Communication Malfunction
• E8       High-Temperature Resistant Protection
• EE       EEPROM Malfunction
• EU      Limit /Frequency Reduction Due to High Temperature of Module
• F0       Refrigerant Defects
• F1       Indoor Ambient Temperature Sensor is Open / Small Circuit
• F2       Indoor Evaporator Temperature Sensor is Open / Small Circulated
• F3       Outdoor Ambient Temperature Sensor is Open / Small Circulated
• F4       Outdoor Condenser Temperature Sensor is Open / Small Circulated
• F5       Outdoor Discharge Temperature Sensor is Open / Small Circulated
• F6       Limit / Decrease Frequency Due to Overload
• F8       Frequency Decrease
• F9       Reduction in Frequency of Due to High Air Discharge
• FH       Limit / Decrease Frequency Due to Anti Freezing
• H0       Frequency of Decreases Due to High-Temperature Resistor During Heating Operation
• H1       Defrosting
• H2       Static Surrender Protection
• H3       Overload Protection for Compressor
• H4       System is Abnormal
• H5       IPM Security
• H6       Internal Motor (Fan Motor) Does Not Operate
• LC       Failure Start-up
• U1       Malfunction of Phase Current Detection Circuit for Compressor
• U3       Malfunction of Voltage Dropping for DC Bus Bar
• U5       Malfunction Current Detection of Complete Units

Error code causes and fixes

Check out the causes of the error codes and how to fix them below;

Error code E1

During cooling and drying operation, except for indoor fan operation, all loads stop operation. During heating operation, the complete unit stops

Possible reasons:

Refrigerant was superabundant

Poor heat exchange (including filth blockage of the heat exchanger and bad radiating environment); Ambient temperate is too high.

Error Code E2

During cooling and drying operation, the compressor and outdoor fan stop while the indoor fan operates

Possible reasons:

Poor air return in the indoor unit.

Fan speed is abnormal.

The evaporator is dirty.

Error code E4

Compressors and outdoor fans stop while indoor fans operate during cooling and drying. During heating operation, all loads stop.

Error code E5

The supply voltage was unstable during operation. Please restart. Contact the dealer or qualified aircon technician if the restart doesn’t work.

Possible reasons:

The supply voltage is unstable.

The supply voltage is too low, and the load is too high.

Evaporator is dirty

Error code E6

During cooling operation, the compressor stops while the indoor fan motor operates. And the complete unit stops during heating operation. As a result, the operation indicator will be off for 3 seconds and blink six times.

Error code E8

The operation indicator is off for 3 seconds and blinks eight times. This is a sign of high temperature-resistant protection.

Error code U8

The operation indicator will go off for 3 seconds and blink 17 times. Circuit PG motor (indoor fan) has circuit malfunction by zero cross detection. The remote controller or control panel operation is available, but the unit won’t act.

Possible cause:

The Control board is damaged.

Error code H1

Defrosting will occur in heating mode. The heating indicator will be off for 3 seconds and blink once. Then the compressor will operate while the indoor fan will stop operation. This is normal.

Error code H4

The system noticed an abnormal temperature range. Please restart. If the restart doesn’t work, contact the dealer or qualified service.

Error code H6

The operation indicator will go off for 3 seconds and blink 11 times. After that, the complete unit will stop operation. The PG motor (indoor fan motor ) does not operate.

Possible reasons:

Poor connection for PGF in the circuit diagram.

Malfunction of indoor units controls panel AP1.

Malfunction of indoor units motor M1.

Error code C5

This is a sign of malfunctioning protection of the jumper cap. The operation indicator will be off for 3 seconds and blink 15 times. Then the complete unit will stop operation.

Possible reasons:

There is no jumper cap on the controller.

The jumper cap is not inserted properly and tightly.

The jumper cap is damaged.

The controller is damaged.

Error code F1

The cool indicator will go off 3 seconds and blink once. This is the sign of the indoor ambient temperature sensor is open/short-circuited. During cooling and drying operation, the indoor unit operates while other loads stop. During heating operation, the complete unit will stop operation.

Possible reasons:

The room temperature sensor hasn’t been connected well with the indoor units control panel AP1

The room temperature sensor is damaged.

Error code F2

The cool indicator will off 3 seconds and blink twice. This is the sign of the indoor evaporator temperature sensor is open/short-circuited. During cooling and drying, the indoor unit operates while other loads stop. During heating operation, the complete unit will stop operation.

Possible reasons:

The room temperature sensor hasn’t been connected well with the indoor units control panel AP1

Room temperature sensor is damaged.

Error code F3

The cool indicator will off 3 seconds and blink 3 times. This is the sign of outdoor ambient temperature sensor is open/short circuited.

Possible cause:

Outdoor temperature sensor hasn’t been connected well or is damaged.

Error code F4

The cool indicator will off 3 seconds and blink 4 times. This is the sign of outdoor condenser temperature sensor is open/short circuited.

Possible cause:

Outdoor temperature sensor hasn’t been connected well or is damaged.

Error code F5

The cool indicator will off 3 seconds and blink 5 times. This is the sign of outdoor discharge temperature sensor is open/short circuited. During cooling and drying operation, compressor wil stop after operating for about 3 mins while indoor fan will operate. During heating operation, the complete unit will stop after operating for about 3 mins.

Possible cause:

Outdoor temperature sensor hasn’t been connected well or is damaged.

The head of temperature sensor hasn’t been inserted into the copper tube.

Error code F6

The cool indicator will off 3 seconds and blink 6 times. This is the sign of limit/decrease frequency due to overload. The aircon status now is all loads operate normally, while operation frequency for the compressor is decreased.

Error code F8

The cool indicator will off 3 seconds and blink 8 times. This is the sign of decrease frequency due to overcurrent.

Possible reasons:

The input supply voltage is too low.

System pressure is too high and overload.

Error code F9

The cool indicator will off 3 seconds and blink 9 times. This is a sign of decrease frequency due to high air discharge.

Possible reasons:

Overload or temperature is too high.

Refrigerant is insufficient.

Malfunction of the electric expansion valve (EKV).

Error code PH

The cool indicator will off 3 seconds and blink 11 times. This is the sign of the voltage for DC bus-bar is too high.

Possible reasons:

Measure the voltage of position L and N on wiring board (XT), if the voltage is higher than 265VAC, turn on the unit after the supply voltage is increased to the normal range.

If the AC input is normal, measure the voltage of electrolytic capacitor C on the control panel (AP1). If it is normal, there is malfunction for the circuit,  replace the control panel (AP1).

Error code U5

The cool indicator will off 3 seconds and blink 13 times. This is the sign of malfunction of complete units current detection.

Possible cause:

There is circuit malfunction on outdoor units control panel AP1,  replace the outdoor units control panel AP1.

Error code P5

The cool indicator will off 3 seconds and blink 15 times. This is the sign of overcurrent protection of phase current for compressor.

Error code H3

The heating indicator will off 3 seconds and blink 3 times. This is the sign of overload protection for the compressor.

Possible cause:

Wiring terminal OVC-COMP is loosened. In the normal state, the resistance for this terminal should be less than 1obm.

Error code HC

The heating indicator will off 3 seconds and blink 6 times. This is a sign of PFC protection.

Error code H0

The heating indicator will off 3 seconds and blink 10 times. This is a sign of decreased frequency due to high temperature resistance during heating operation. All loads operate normally, while operation frequency for compressor is decreased.

Error code LC

The heating indicator will off 3 seconds and blink 11 times. This is a sign of a failure start-up.

Error code U1

The heating indicator will off 3 seconds and blink 13 times. This is the sign of malfunction of the phase current detection circuit for compressor.

Possible fix:

Replace outdoor control panel AP1

Error code EE

The heating indicator will off 3 seconds and blink 15 times. This is the sign of EEPROM malfunction.

Possible fix:

Replace outdoor control panel AP1

Error code PU

The heating indicator will off 3 seconds and blink 17 times. This is the sign the charging malfunction of capacitor.

Error code P7

The heating indicator will off 3 seconds and blink 18 times. This is a sign of malfunction of module temperature sensor circuit.

Possible fix:

Replace outdoor control panel AP1

Error code P8

The heating indicator will off for 3 seconds and blink 19 times. This is a sign of module high-temperature protection.

Possible fix:

After the complete unit is de-energized for 20 mins, check whether the thermal grease on the IPM module of outdoor control panel AP1 is sufficient and whether the radiator is inserted tightly. If it is no use, replace control panel AP1.

Error code U3

The heating indicator will off for 3 seconds and blink 20 times. This is the sign of malfunction of voltage dropping for the DC bus bar.

Possible cause:

The supply voltage is unstable.

Error code U7

This is a sign of the four-way valve is abnormal. If this malfunction accors during heating operation, the complete unit will stop operation.

Possible reasons:

The supply voltage is lower than AC175V.

Wiring terminal 4V is loosened or broken.

4V is damaged. Replace 4V.

Error code U9

This is a sign of zero-crossing malfunction of the outdoor unit.

Possible fix:

Replace outdoor control panel AP1.

Error code PL

The heating indicator will turn off for 3 seconds and blink 21 times. This is a sign that the voltage of the DC bus bar is too low.

Possible fix:

Measure the voltage of positions L and N on the wiring board (XT). If the voltage exceeds 150VAC, turn on the unit after the supply voltage is increased to the normal range.

If the AC input is normal, measure the voltage of electrolytic capacitor C on the control panel (AP1). If it is normal, there is a malfunction of the circuit. Therefore, replace the control panel AP1.

Error code EU

This is the sign of limit/decreased frequency due to high temperature of module.

Possible fix:

Discharging after the complete unit is de-energized for 20 mins, then check whether the thermal grease on the IPM module of outdoor control panel AP1 is sufficient and whether the radiator is inserted tightly. If it is no use, replace the control panel AP1.

Error code FH

This is the sign of limit/decreased frequency due to antifreeze.

Possible cause:

Poor air return in the indoor unit or fan speed is too low.

Why is my Friedrich Air Conditioner Leaking Water Inside?

A Friedrich Air conditioner will leak water if the humidity levels are too high in the living space, the condensate drain is overflowing, the drain pipe of the indoor unit is loose or detached, or there’s ice on the evaporator coils.

High Humidity Levels in the Living Space

Your AC removes heat and moisture from the air in your room and cools it to send it back. The heat and moisture removed from the air are used in the cooling process to enhance the AC’s efficiency, and the excess moisture is drained out of your cooling unit.

High humidity in the room (above 50%) will not only make you feel uncomfortable and reduce the efficiency of your AC but also produce excess moisture, which can overflow the drain pan and cause leaks.

How to Diagnose High Humidity Levels

Depending on the model, your AC’s thermostat will show the moisture levels on the control panel. Any levels higher than 50% are considered high moisture range.

High humidity levels in your home/room are also marked by: 

A moist feeling in the air.

A musty and damp smell around the home/room.

A foggy build-up of moisture on the windows.

How to Fix High Humidity Levels

Moisture levels in a room that’s being cooled will eventually go down after running the AC for some time.

However, you can reduce humidity levels in your home by:

Running your AC on the Dry Mode for 1-2 hours.

Installing a dehumidifier.

Ensuring your HVAC ductwork has no leaks.

Using exhaust/ventilation fans in high moisture areas like the kitchen and shower.

Temporary relocating indoor plants to an outdoor place.

Condensate Drain Overflow

Excess moisture from the cooling process is sent to the drain pan and out through the condensate pipe into the main drain line.

If any part of this drain system is blocked or, owing to excess humidity, there’s too much water getting into the drain pan. As a result, the condensate drain may overflow.

How to Fix an Overflowing Condensate drain

Suppose your condensate drain is overflowing due to high moisture levels and the excess water produced during the cooling process. In that case, you might need to drain the condensate pan manually by absorbing the water with a sponge or rug and squeezing it into a bucket.

Combine draining the condensate pan with the humidity-reducing measures discussed above.

If the humidity levels in your home are within the average range, but your drain pan is overflowing, the condensate drain may be clogged.

If that is the case, follow the steps to fix a blocked condensate drain described earlier in the section on “Friedrich Air Conditioner Not Draining.”

Loose, Detached, or Cracked Drain Pipe

If the drain pipe attached to your AC drain pan is loose, detached, or cracked, it can send water to the wall and the areas around the AC.

How to Diagnose and Fix a Loose/Detached Drain Pipe

Simply access the drain pipe at the bottom of the indoor unit and assess it for loose connections or cracks. Then, reattach a loose or disjointed drain pipe and replace a cracked pipe to stop the leak.

Frozen Cooling Coils

If your Friedrich AC has frozen cooling coils, it will produce more water from the melting ice.

How to Detect Friedrich AC Frozen Cooling Coils

If your suspect that the coils in your Friedrich AC indoor unit are frozen, open the unit to check it for ice build-up by following these steps:

Remove the front panel of your indoor unit.

Remove the filter by lifting it from the center part and pulling it towards you. The cooling coils are right behind the filter.

Check the coils for ice build-up.

How to Fix Frozen Friedrich AC Cooling Coils

To get rid of ice on your Friedrich AC cooling coils, switch off the cooling unit and leave it for a few hours to allow the ice to thaw.

You can also set your AC’s thermostat at Med Fan or High Cool to speed up the thawing process.

Why is the Friedrich Air Conditioner Fan Not Working?

If your Friedrich air conditioner fan is not working, the AC could be running on the defrost Mode, the fan motor may be defective, the thermostat may be faulty, or the control board is faulty. A defective fan motor may happen more often and should be repaired/replaced by an HVAC expert.

Check this too: How to Vent a Portable Air Conditioner Without a Window

Defrost Mode

If you use your Friedrich AC in the Heat Mode during low temperatures, frost may form on the outdoor unit. In that case, the unit will go into Auto defrosting Mode, and the fan in the indoor unit will stop running.

How to Tell if your Friedrich AC is on Defrost Mode

When in defrost Mode, your Friedrich AC will show these indications:

Read Defrost Mode on the panel.

The indoor indicator will be flashing.

The outdoor unit will emit vapor as the frost thaws.

What to Do if the AC Fan is in Defrost Mode

If your Friedrich AC indicates Defrost mode, simply allow it to defrost. This will take 8-10 minutes, and the AC will resume the previous heating function.

Defective Fan Motor

A defective fan motor may have worn-out parts or voltage issues. As a result, the fan will not spin to send the cooled air to your home.

How to Diagnose a Defective Fan Motor

Open the AC compartment that houses the fan and try turning it manually. If the fan is hard to spin, the fan motor bearings are worn out and need replacing. If, instead, the fan spins easily, there could be voltage issues.

How to Fix a Defective Friedrich AC Fan Motor

If you test your Friedrich AC fan motor for continuity and there are no voltage issues, the fan motor is most likely defective.

A defective Friedrich AC fan motor should be checked and serviced/replaced by a trained HVAC expert.

Faulty Thermostat

Every time your Friedrich AC runs, it receives a signal from the thermostat that the temperature in the room is above the set level, and it’s time to run the next cooling cycle.

If your Friedrich AC thermostat is faulty and does not send the signal, the fan will not work.

How to Diagnose a Faulty Thermostat

Normally, a faulty thermostat will show error codes or a blank screen. If that’s the case, check to ensure that the thermostat is not set on Auto mode. If the thermostat is set on Cool Mode, use a multimeter to test it for continuity.

How to Fix a Faulty Friedrich AC Thermostat

A faulty thermostat will have to be replaced. Hire the services of a reliable HVAC technician first to confirm that your AC thermostat has malfunctioned and consequently replace it.

Malfunctioning Control Board

The control board of your AC manages the voltage supply to parts of the AC, including the fan motor.

If the control board should malfunction, the voltage will not be sent to the parts as it should, which could cause the fan not to run.

How to Diagnose and Fix a Malfunctioning AC Control Board

The control board is one of the AC parts that should not be diagnosed or serviced by someone who’s not an expert.

Contact an HVAC pro if you suspect your Friedrich AC control board is malfunctioning. The HVAC pro will test the control board for continuity with a voltmeter, repair any faulty parts, or replace the entire control board if the case requires it.

Bad Rotary Knob/Switch

For Friedrich AC models that use a rotary knob/switch, you need to turn the knob to select the fan’s speed.

If the rotary knob is bad due to wear and tear or has lost continuity with reduced electrical conduction, your fan will not respond to the rotary knob.

How to Diagnose and Fix a Bad Rotary Knob/Switch

A multimeter will show if there’s continuity in the rotary switch. However, since it might not be obvious to you which among the wires in your AC controls voltage to the rotary knob, you are better off calling an HVAC expert to test the rotary switch for continuity and replace it if needed.