31
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Rinnai · Tankless Water Heaters
Burner sensor error.
Quick Answer
Error code 31 on your Rinnai Tankless Water Heaters means: Burner sensor error.. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Power cycle once to clear transient state.
2
Inspect visible harness connections if accessible.
3
Have technician measure sensor resistance.
4
Replace faulty burner sensor if out of spec.
5
Verify code clears after repair.
Pro Tip
This issue typically requires professional diagnosis. Attempting this fix without proper training could cause further problems.
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