Error Codes on a Rheem 27

Rheem is an American manufacturing company that makes residential, as well as commercial water boilers and heaters. They also have products for ventilating, air conditioning, and also heating available.

Rheem 27

Focusing on the Rheem 27, this is a water heater with the highest capacity continuous flow gas water heater. This is called the 27 because it has a 27L/minute capacity, which delivers extra hot water should the need arise. This product is perfect for large families where a large amount of hot water is needed but with a small space. This has several features and includes:

A capacity of 27 Liters
It can be used by up to 4 to 6 people
Lastly, it has an energy rating of 6.

Troubleshooting Rheem Tankless Error Codes

Troubleshooting a tankless water heater could appear confusing but if you get to know what the error codes mean, it could become an easy task although having a wireless monitoring or app is a great help in identifying issues with your Rheem tankless water heaters. There are issues that can be fixed by yourself but some would need professional help to get it fixed. However, should you be in a situation where an error code is displayed, the first thing that you should do is turning off your water tap, then do the same to the remote control, wait for at least 5 minutes before turning it on again and lastly open the hot water faucet. If there are no changes and an error code is still displayed, then what should be done is close off the hot water tap and the remote should be turned off. You can also use the error guidelines listed but we recommend calling a technician so that any problem can be checked thoroughly and professionally.

List of Tankless Water Heater Error Codes

Error Code 1L	There may be deposits of Limescale or scale in the heat exchanger, which causes for water flow to reduce and the temperature to increase. To address this, you should descale the water heater flush the heat exchanger wherein one must check with the owner’s manual for complete instructions.
Error Code 05	This could be because of a blockage in the air supply pipe or the exhaust vent. Another thing to check is that the connection or termination may be loose or incorrectly done. The unit may still operate but you may hear an alarm sound every 60 seconds when the tap is open. The venting system should be checked for problems or what is blocking the vent should be removed if you are having problems finding the cause; a professional service should be called. It should also be noted that the vent system was done according to requirements and that the fan motor should be checked as well.
Error Code 10	Blower motor could not be working properly or a false flame has been detected. What to do in a case such as this is to ensure that all vent and heat exchange components are clean and are connected properly. Fuel inlet and exhaust should be free of blockage and one has to make sure that the proper vent materials are used. One should also make sure that the maintenance is up to date.
Error Code 11	There is no ignition which could be because of gas supply or installation error. This could also be because the gas shut-off valve is not completely open. To address this, one has to make sure that the gas pipe is open. The gas type, pressure and volume should be checked and one should make sure that they match the system’s requirements. The air in the gas line should be emptied and that the gas line, regulator and meter are the right size. Connections should be checked and made sure that the unit is accurately grounded.
Error Code 12	There is a flame failure or the heater can’t maintain a flame. This could be because of having not enough gas because of an interruption in gas supply from the distributor if you are using natural gas and a tankless water heater. If propane gas is used, you must make sure that you have enough gas in your propane tank.
Error Code 13	There may be indoor venting where a flame rod warns of poor and improper combustion. In cases like these, you can consult the owner’s manual or you can contact a professional. Have the proper installation requirements wherein the intake and exhaust vents meet the requirements thus ensuring a safety operation.
Error Code 14	The overheat wrap is experiencing problems or fault. This could be due to maintenance error or flue pipe is overheating. The mid-efficiency and condensing units have faults in the Overheat Limiter (OHL). One has to make sure that the proper gas type is being used and the high fire and low fire manifold pressures are correct. Cracks or openings should be checked including air flow restrictions around the vent terminal and unit. A foreign object may also be present in the combustion chamber and exhaust pipe work.
Error Code 15	When you get an error code 15 this means a boiling safety warning. This could be because the water tap is not fully opened therefore water flow is low which causes excessive temperature of the heat exchanger. One should check that the cold water inlet pipe and inlet valve is fully open and also one has to make sure there is no blockage.
Error Code 16	This is a warning on excessive temperature where heater has already exceeded safe water heat levels. One has to make sure that the outlet water is not above preset thermostat settings. In cases such as this, it should be checked that the combustion chamber, exhaust pipes, heat exchanger and vent terminal have no blockages.
Error Code 21	The air intake filter intake switch is malfunctioning. One has to make sure that the air filter door is seated properly and there should be correct installation of the front panel.
Error Code 24	The Error Code 24 means there is a malfunction in the operational switch. In cases such as these, the unit should be restarted, connections should be checked. In cases where even after the button is reset and it still doesn’t work, the PCB should be replaced.
Error Code 29	This is telling you that there could be a clogged neutralizer. It could also be that the heat exchanger output temperature is too low. If this appeared it could be that the heat exchanger air inlet needs to be cleaned. One has to make sure that the drain line is not blocked and if everything still does not work, a technician should be called.
Error Code 31	When Error Code 31 is seen, there could be a problem with the water inlet temperature sensor. If this is seen, the sensor wiring should be checked for any damages and scales should be cleared.
Error Code 33	There could be issues with the outgoing water temperature sensor. The sensors should be checked for wire damages and scales should be cleaned off. One should Ohm out the sensor. If necessary, the sensors should be replaced.
Error Code 34	Issues in the temperature combustion air temperature sensor for example the wiring. The sensors should be cleared of scales and checked for damages. It should be made sure that there are no restrictions to the air flow and that the fan blades should be in good shape and tightly attached to the motor shaft. Just like with Error Code 33, Ohm out the sensor and a replacement should be done if deemed necessary.
Error Code 35	There is incorrect connection with the thermistor. Make sure there is proper connection between the thermistor and the control board.
Error Code 51	If you are seeing Error Code 51, this means that there is a problem with the gas control valve. The gas control valve should be Ohm out and one should check for any loose or damaged terminals to the wiring of the gas control valves.
Error Code 52	This means that there are problems with the PFGR (Proportional Gas Flow Regulating) valve. Ohm out the valve and then it should be checked for any loose or broken connections.
Error Code 61	There is a failure of the combustion fan. Make sure that there is no damage to the wiring harness or motor and that all connections are tight. There should be minimal resistance when fan motor is turning and the length of the venting should also be checked.
Error Code 71	There is a problem with the gas solenoid valve control. The gas inlet solenoid valve wiring harness should be checked for damages or loose terminals and ohm out the valve.
Error Code 72	Issues with the flame sensing device. This could be because of an issue with the flame rod therefore it should be made sure that there is no damage to the wiring and that it is providing the proper voltage. The burner chamber should be clear from any blockages.
Error Code76	There is an error with regards to the communication of the remote control. Make sure that there are no damaged or loose connections and in worst cases, the remote control may need to be replaced.
Error Code 79	There is a problem with the fan motor current. One should make sure that there is minimal resistance when the fan motor is turning and that the motor is receiving the proper voltage. In worst cases, the fan motor or the PCB may need to be replaced.
Error Code 80 and 81	There is failure in gas cut-off. The voltage of every flame rod should be checked and Ohm out the solenoid valves. If it becomes necessary the gas control valve needs to be replaced.
Error Code 82	There is a problem determining the gas type which could be because the control board is not programmed properly. The PCB should be programmed to the proper gas type and that one should make sure that there is proper installation.
Error Code 99	This means that the blower motor is not venting or the flue could be blocked. Blockages should be checked and then cleared in the combustion fan, exhaust flue, heat exchanger and then the inlet filter.

We would recommend that a qualified person opens the appliances or attempts a repair. These are only to provide you with information and serve as a guide to help identify the fault. In case your are having doubts, you can give Water Heater Brokers NZ (Water Heater Brokers) a ring. We have installed water heaters for years and that our staff have the necessary experience and skill to assist your needs from start to completion of the work. Just get in touch with us if you have any questions.