A031 🟡 Repair Required
Rheem Error Code A031: Inlet Thermistor Open/Short
⚠️ Your Rheem HVAC system has detected an issue with the inlet thermistor and has shut down to prevent damage.
How to Fix Rheem Code A031
- Step 1: Turn off the power to your HVAC system at the circuit breaker.
- Step 2: Inspect the wiring leading to the inlet thermistor for any visible damage or disconnection.
- Step 3: If you're comfortable, check the thermistor's resistance using a multimeter. If it's not within the specified range (usually between 10,000 to 100,000 ohms), it may be faulty. If not, call a professional HVAC technician.
What Does Rheem Error Code A031 Mean?
The Rheem A031 error code indicates that there's an open or short circuit in the inlet thermistor, which is responsible for measuring the temperature of the incoming air. This could be due to a faulty thermistor, a broken wire, or a problem with the circuit board. The system has entered a safety lockout mode to protect itself from further damage. You'll need to address this issue to restore normal operation.
Common Causes of Rheem Code A031
- Faulty inlet thermistor
- Broken wire leading to the thermistor
- Issue with the circuit board
Applicable Rheem Models
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Find a Licensed Tech Near You →Replacement Parts for Rheem Tankless Water Heater Code A031
Inlet Thermistor OEM: 40-00103