Code 37 — Heater output sensed on when not energized

What does 37 mean?

This code indicates a fault where the heater is detected as being on even when it should not be receiving power. This can affect heating performance and safety.

• Faulty heater output sensor
• Wiring issue to the heater output
• Control board malfunction

Click steps to track your progress.

1. 1

   Check heater output wiring for damage or loose connections.

2. 2

   Verify the control board is functioning correctly.

3. 3

   Contact an HVAC technician for further diagnosis and repair.