Rheem Tankless Water Heaters: Error Codes

If you own a Rheem tankless water heater and encounter any of the error codes listed below, it’s crucial to take immediate action to avoid damage to the unit and in extreme cases personal injury. While it’s helpful to be familiar with these codes and their potential causes, attempting to diagnose or repair the unit on your own can be dangerous and can lead to further damage.

Instead, it’s recommended to contact a professional Water Heater Technician who specializes in tankless water heaters and can properly diagnose and repair your tankless water heater. These technicians have the necessary tools, expertise, and training to safely troubleshoot and repair your unit.

Understanding Rheem Tankless Water Heater Error Codes

Here is a comprehensive list of Rheem tankless water heater error codes and their meanings:

• Rheem Error Code 00 – This code indicates a power interruption or power supply problem. Check the power source and connections.
• Rheem Error Code 11 – This code indicates a problem with the ignition or ignition sensor. Check the sensor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 12 – This code indicates a problem with the flame sensor. Check the sensor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 13 – This code indicates a problem with the gas supply or gas valve. Check the gas supply and valve, and replace or repair them as necessary.
• Rheem Error Code 14 – This code indicates a problem with the thermal fuse. Check the fuse and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 15 – This code indicates a problem with the inlet water temperature sensor. Check the sensor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 16 – This code indicates a problem with the outlet water temperature sensor. Check the sensor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 21 – This code indicates a problem with the overheating sensor. Check the sensor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 24 – This code indicates a problem with the flow sensor. Check the sensor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 29 – This code indicates a problem with the neutralizer. Check the neutralizer and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 31 – This code indicates a problem with the inlet water filter. Check the filter and clean or replace it as necessary.
• Rheem Error Code 32 – This code indicates a problem with the heat exchanger. Check the exchanger and clean or replace it as necessary.
• Rheem Error Code 33 – This code indicates a problem with the combustion air supply. Check the air supply and connections, and clean or repair them as necessary.
• Rheem Error Code 35 – This code indicates a problem with the fan motor. Check the motor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 51 – This code indicates a problem with the gas valve or wiring connections. Check the valve and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 52 – This code indicates a problem with the modulating gas valve or wiring connections. Check the valve and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 61 – This code indicates a problem with the fan motor or wiring connections. Check the motor and wiring connections, and replace or repair them as necessary.
• Rheem Error Code 70 – This code indicates a problem with the communication between the
  control board and the remote control. Check the connections and reset the remote control.
• Rheem Error Code 71 – This code indicates a problem with the communication between the control board and the water flow control valve. Check the connections and replace or repair the valve as necessary.
• Rheem Error Code 72 – This code indicates a problem with the communication between the control board and the remote control. Check the connections and reset the remote control.

It’s important to note that attempting to diagnose or repair your Rheem tankless water heater on your own can be dangerous and can potentially cause further damage to the unit. Ignoring these error codes and continuing to use your Rheem tankless water heater with a potential issue can result in further damage and even more costly repairs down the line. In some cases, it can even be dangerous.

So, if you encounter any error codes with your Rheem tankless water heater, don’t hesitate to contact a qualified service provider for assistance. They can help you avoid potential harm and ensure your unit is functioning properly.

THE Water Heater Company is a small family-owned and operated business. If you are in our service area and need assistance with your tankless water heater, give us a call. We look forward to helping you with your water heater repair and maintenance needs.