10 flashes
Moderate
Rheem · HVAC Systems & Water Heaters
12VDC Flame Sense Circuit Fault
Quick Answer
Error code 10 flashes on your Rheem HVAC Systems & Water Heaters means: 12VDC Flame Sense Circuit Fault. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Disconnect the flame sensor wire and check the sensor resistance to ground (should be open/infinite)
2
Inspect the flame sensor wire insulation for damage that could cause grounding
3
Verify the flame sensor is not physically contacting the burner or chassis ground
4
If the sensor and wiring check out, the control board flame sensing circuit is likely failed
5
Control board replacement should be performed by a licensed HVAC technician
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Control board
Flame sensor
Sensor wire and connector
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