Rinnai Code 31 — Cold Water Inlet Temperature Sensor Fault

What Causes Rinnai Code 31?

The inlet thermistor is reading outside its normal range. Can be caused by wiring damage, corrosion, or sensor failure.

How to Fix Rinnai Code 31

Sensor replacement required. We carry Rinnai V-Series and RU-Series sensors and can complete this repair prompt throughout Los Angeles.

When to Call a Professional

Call Simple Water Heater & Filtration if:

• The error code returns after resetting
• You are not comfortable working with gas appliances
• The unit is making unusual sounds alongside the error
• This is the second time you have seen this code in the past year

We are factory-trained on Rinnai and provide repair service throughout Los Angeles, the San Fernando Valley, Westside LA, and Ventura County.