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Rheem Water Heater Troubleshooting & How to Guide

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Rheem Water Heater Troubleshooting & How to Guide

Rheem offers a range of quality water heaters for residential and commercial purposes. The units are undoubtedly reliable, durable, and offer good value for money. However, a problem may arise on your Rheem water heater and will need to be fixed to keep it running smoothly and effectively. Before you call a technician for a problem you might have with your water heater, it helps to perform some simple troubleshooting steps. Some problems are minor operational issues or conditions that only require simple DIY fixes to resolve.

How to troubleshoot Rheem water heater

Not enough or no hot water from the heater

  1. Check your household’s water usage. If the usage exceeds the water heater’s capacity, wait for the water heater to fully recover.
  2. Check the water heater’s power supply. Check for blown fuses or a tripped circuit breaker. Ensure the disconnect switch, if used, is in the on position.
  3. If it is gas heater, check that the water heater is receiving fuel by ensuring that any cutoff valves in the gas line are turned to the on position. Have other gas water heater problems looked into and serviced by a qualified technician.
  4. Check the water heater thermostat for proper setting, and readjust the setting if needed.
  5. Ensure that all faucets are closed and are not leaking.
  • If your water heater makes a rumbling noise, remove and clean the heating elements. This is due to a mineral scale build up on the elements.
  • If the relief valve makes a popping sound or drains water, this is due to excessive pressure in the plumbing system. Contact a qualified plumber to have your system checked out.
  • If the water is coming out too hot, adjust the thermostat on the water heater.

Why is my Rheem water heater not heating?

There could be several reasons why your water heater is not heating:

  1. Your electric supply may be off and there is no power going to your water heater. You need to make sure electric supply to water heater and disconnect switch, if used, are in the ON position.
  2. Electric service to your home may be interrupted. Confirm whether your home and nearby homes have power. Contact the local electric utility if there is power interruption in your home.
  3. A fuse may be blown or a circuit breaker tripped. Check for blown fuses and tripped circuit breaker. Replace fuse if blown or reset circuit breaker to fix the problem.
  4. The temperature limiting control (ECO) could have broken the power circuit to the heating element after sensing excessively high water temperatures. To fix the problem, you must manually reset the ECO.
  5. The thermostat may be set too low. You can regulate the temperature of the water in the water heater by setting the temperature dial of the adjustable surface mounted thermostat located behind the jacket access panel.
  6. Leaking or open hot water faucets. Make sure all faucets are closed.
  7. During winter months, the cold water inlet temperature may be colder. This is normal. The cold water inlet takes longer to heat.
  8. If the issue doesn’t resolve after checking the above issues, there could be a problem with your wiring. Make sure power supply voltage agrees with your water heater rating plate. The branch circuit wire and fusing or circuit breaker should be of proper size. Also, make sure that the electrical connections are tight and the unit is properly grounded. Refer to installation instructions that came with your unit.

How do I reset my Rheem water heater?

Rheem electric residential water heaters (HE, GE, PE, and SE Series) are equipped with a combination thermostat and temperature limiting control (ECO) that is located above the heating element in contact with the tank surface. If the water temperature, for any reason, becomes excessively high, the ECO breaks the power circuit to the heating element. Once the control opens, you must reset it manually.

To reset the temperature limiting control:

  1. Turn off the power to the water heater.
  2. Remove the jacket access panels and insulation. Do not remove the thermostat protective cover.
  3. Press the red reset button.
  4. Replace the insulation and jacket access panels before turning on the power to the water heater.

Rheem water heater troubleshooting codes (continuous flow water heater)

Error/troubleshooting codes are displayed on the LED display on the front of your Rheem continuous flow water heater. Below is a listing of the various error codes and what they mean:

  1. Error code 03-EZ Link
  2. Error code 05- Imperfect Combustion Alarm
  3. Error code 10- Abnormal low rate combustion
  4. Error code 11- Ignition failure at start up
  5. Error code12- Flame failure during operation
  6. Error code 14- Overheating
  7. Error code 15- Very high temperature
  8. Error code 16- Outlet water temperature too high
  9. Error code 24- Operational switch faulty
  10. Error code 29- Heat Exchanger Outlet Temperature too low
  11. Error code 31- Inlet thermistor open circuit
  12. Error code 32- Heat exchanger thermistor open circuit
  13. Error code 33- Outlet thermistor open circuit
  14. Error code 34- Ambient air thermistor open circuit
  15. Error code 35- Thermistor connections crossed
  16. Error code 51- Gas cut off malfunction (SV0 failure)
  17. Error code 52- P.G.R.F control failure
  18. Error code 56- Bypass solenoid failure
  19. Error code 61- Abnormal fan speed or fan failure
  20. Error code 65- Malfunction of water volume control motor
  21. Error code 66- Water By-Pass Control Fault
  22. Error code 71- G.I.S valve control failure
  23. Error code 72- Detected false flame
  24. Error code 73- Vent type control data failure
  25. Error code 74, 75, or 76- Communication problem between remote controller and water heater
  26. Error code 79- Fan motor current detection failure
  27. Error code 80- Gas cut off defective
  28. Error code 81- No false flame detected
  29. Error code 82- Functional problem on gas type circuit board
  30. Error code 90- Decrease in fan motor ventilation
  31. Error code 99- Decrease in fan motor ventilation. (Operation stop)

Rheem water heater reset button location

The reset button on a Rheem water heater is the red button located in the center of the limit switch just above the water heater thermostat.

Rheem water heater blinking light codes

There are fault codes that can be shown through the amount of blinking lights on the Rheem heat pump controller. The blinking light codes vary depending on the unit, either 310L or 325L.

On the 310 series Heat Pumps, there are two variations of LED indication depending upon the version of the controllers software; however all versions use a red and green LED to display the operational status and/or fault condition of the appliance.

For controller software version HPV 3.1, HPV 3.2 or no HPV identification:

  1. Green Solid- Standby mode (end of heating cycle, cylinder water at required temperature).
  2. Green Flashing- Call for heat initiated.
  3. Red Flashing- Component fault or ambient conditions too cold for heat pump operation.
  4. No indication- Fault or system in limp mode with call for heat satisfied (water in cylinder at 700C determined by mechanical thermostat).

Controller version HPV 4.0 or higher

If no fault is present the green LED will flash to indicate the operation sequence number the heat pump is currently operating in:

  1. Green solid- Sequence 0
  2. Green 2 flashes- Sequence 2
  3. Green 3 flashes- Sequence 3
  4. Green 4 flashes- Sequence 4

If a fault is present, the green and/or red LEDs will indicate the fault condition according to the list below:

  1. Green 0, Red 0-Faulty power supply or system in limp mode with call for heat satisfied
  2. Green 1 flash, Red 0- T3 (comp dis) > 600C in sequence 0 (This condition creates a delay start for the compressor. This is not considered a fault.)
  3. Green 0, Red solid- T4 (ambient air) < 00C (Ambient temperature too cold for heat pump. This is not considered a fault.)
  4. Green 0, Red 1 flash- Any Sensor Strip Sensor Fault
  5. Green 0, Red 2 flashes- Water circ fault TO (water outlet) > 800C
  6. Green 0, Red 3 flashes- T2(Evaporator) < -30C
  7. Green 0, Red 4 flashes- Comp/refrig fault T3> T4 + 150C (in seq3)
  8. Green 0, Red 5 flashes- Comp/refrig fault T0 –T1 < 80c (in seq4)
  9. Green 0, Red 6 flashes- Water circ fault T1> s4 + 70C
  10. Green 0, Red 7 flashes- TRIAC/refrig fault T3> 1100C
  11. Green 1 flash, Red 1 flash (simultaneously)- Thermistor T0 Fault
  12. Green 2 flashes, Red 2 flashes(simultaneously)- Thermistor T1 Fault
  13. Green 3 flashes, Red 3 flashes(simultaneously)- Thermistor T2 Fault
  14. Green 4 flashes, Red 4 flashes(simultaneously)- Thermistor T3 Fault
  15. Green 5 flashes, Red 5 flashes(simultaneously)- Thermistor T4 Fault

Why is my water heater only lukewarm?

The water temperature may be lower than usual due to heavy hot water usage.Your water usage may have exceeded the capacity of the water heater. Please wait for the heater to recover after an abnormal demand.

Also, this problem could be due to faulty tempering valve that is excessively cooling your hot water. Have your system tested by a plumber and replace the valve if necessary.

If you have a solar water heater, check that the booster is being used as per the installation instructions for your model. If you have a timer installed, you will need to ensure that sufficient time is allowed to heat enough water to meet your household’s hot water needs.

If you have a 500C temperature limited water heater then hot water to your whole house will be limited to 500C.

Rheem gas water heater pilot light how to and troubleshooting

How to light a Rheem water heater pilot

Rheem water heater pilots need to be manually lit using the piezo ignitor striker built into the water heater. Follow the steps below to light your water heater pilot:

  1. Rotate the gas knob on your Rheem water heater clockwise until it is in the “Off” position.
  2. Rotate the water heater temperature dial counterclockwise until it is set to the lowest temperature setting. Wait 5 minutes to allow any gas in the water heater to pass through.
  3. Lift off the outer door of your water heater. Rotate the gas knob counterclockwise until it is in the “Pilot” position.
  4. Push down the red button to the left of the gas knob. Hold the button down while pressing the piezo ignitor striker, located on the immediate right of the gas knob, repeatedly until the pilot is lit. You can see the pilot light through the viewing window on the water heater’s inner door. Keep holding down the red button for 1 minute after the pilot is lit, and then release it. The pilot will remain lit.
  5. Replace the outer door to your water heater. Rotate the gas knob counterclockwise until it is in the “On” position. Set the hot water temperature dial to your preferred water temperature.

Pilot light won’t  light or stay lit

If the pilot light on your Rheem water heater won’t light or stay lit, it could be because of a blocked gas line. Other possible causes for this problem are a faulty thermocouple, malfunctioned gas valve, or something as minor as draft coming from a crack in the wall or under the door.

To troubleshoot the problem, follow these instructions:

  • Open the valve on the gas line by turning the handle until it is parallel to the gas pipe. Turn the gas control knob to the “Pilot” position and push it in. Can you hear a faint hissing sound? If not, there may be a blockage on the pilot supply tube, or the heater gas tube may be faulty.
  • Turn off the gas, disconnect the pilot supply tube using a small wrench and clean it out with compressed air. If the problem persists, you may need to clean or replace the gas valve.
  • Light the pilot if you hear a hissing sound when you depress the gas control valve. If the flame starts but goes out shortly, check for drafts. Inspect the vent if you can’t find the source of draft in the room. It should extend 18-24 inches above the roof line and be free from obstructions. Even a small breeze will blow the pilot if the vent is too short.
  • If the flame stays lit while holding down the button but goes out when you release it, adjust the thermocouple. This is the small device, shaped like a bulb, located near the pilot aperture. Check to make sure the thermocouple isn’t loose and fell slightly out of position.
  • Replace the thermocouple if adjusting it doesn’t fix the problem. Turn off the gas, then disconnect the thermocouple, pilot tube, burner gas supply and pilot igniter from the gas valve and remove the sealed access door. Install a new sealed access door after replacing the thermocouple to prevent carbon monoxide getting into your home.
  • If the above steps don’t fix the problem, contact your gas or propane supplier to inspect your service lines. The gas could be contaminated by water or oil that is restricting the gas flow.

Check this too: Mr. Heater troubleshooting & How-to Guide

Rheem water heater overheating

Likely causes for an overheating water heater include:

  • Temperature setting being too high
  • Malfunctioning thermostat
  • High mineral content
  • Blocked pressure relief valve

If your Rheem water heater is overheating, try these troubleshooting tips to fix the problem:

  1. Check the thermostat and adjust lower if necessary. Sometimes the dial is tweaked too high accidentally.
  2. In time, mineral settle around the heating element. When these heating elements get coated with sediment, they have to work harder to heat the water. This may lead to the elements overheating, which is why your water heater is suddenly hot. Check the heating elements for mineral scale build up. Remove and clean the heating elements if necessary.
  3. The pressure relief valve allows buildup steam to escape from inside the water heater. If this valve is blocked, your hot water will come out hotter than normal. If you can hear water boiling inside your water tank, you need to shut down the power to your heater immediately as this could cause an explosion. Call a qualified plumper to have it checked out after shutting off your water heater.
  4. If your water heater is still overheating even after adjusting the thermostat accordingly, the thermostat could be faulty. You need to replace the thermostat.
  5. If adjusting the dial on your gas water heater doesn’t fix the problem, replace the valve assembly,