31 🟡 Repair Required
Rinnai Error Code 31: Inlet Thermistor Failure
⚠️ Your Rinnai water heater is locked out and needs professional attention to prevent water supply interruption.
How to Fix Rinnai Code 31
- Check if the water heater is receiving power. If not, reset the GFCI outlet or replace the fuse.
- If the water heater has power, do not attempt to fix the issue yourself. Contact a professional HVAC technician.
What Does Rinnai Error Code 31 Mean?
Rinnai's error code 31, Inlet Thermistor Failure, indicates a problem with the sensor that measures the temperature of the incoming water. This sensor helps regulate the water heater's operation and ensure safety. If it malfunctions, the water heater will shut down to prevent overheating or freezing, displaying error code 31 on the digital display.
Common Causes of Rinnai Code 31
- Faulty inlet thermistor
- Wiring issue between the thermistor and the control board
- Control board malfunction
Applicable Rinnai Models
Need a Pro to Fix Rinnai Code 31?
A licensed HVAC technician can diagnose and fix this issue quickly.
Find a Licensed Tech Near You →Replacement Parts for Rinnai Tankless Water Heater Code 31
Inlet Thermistor OEM: RIN-12010100
Control Board OEM: RIN-12020000