Rinnai Tankless Water Heater Error Code 79: How to Fix It

Q: Can I fix Rinnai error code 79 myself?

Yes, if you are comfortable working with water heaters and have basic tools, you can often clear the pump rotor lock by cleaning the pump. Always follow safety precautions.

Q: What causes error 79 on a Rinnai water heater?

Error 79 is caused by a locked pump rotor, usually due to mineral scale, debris, or sediment buildup in the pump. Hard water can accelerate this.

Q: How do I reset my Rinnai after fixing error 79?

After repairing, press the reset button on the control panel. If there is no reset button, turn the unit off and on using the power switch. The error should clear if the pump is free.

Q: Do I need to replace the pump for error 79?

Usually, cleaning the rotor is sufficient. However, if the pump is damaged or the rotor cannot be freed, you may need to replace the circulation pump.

Q: Will error 79 damage my Rinnai water heater?

Ignoring error 79 can lead to overheating or damage to the heat exchanger. It's best to address it promptly to prevent further issues.

Abstract

Error code 79 on a Rinnai tankless water heater indicates a pump rotor lock. This means the pump's rotor has jammed, often due to debris or mineral buildup. Follow these steps to clear the blockage and restore hot water.