How to Fix / Troubleshooting

Critical safety warning: Do not repeatedly reset a breaker that continues to trip. This indicates a potentially dangerous electrical fault.

1. Note when it trips: Observe whether the breaker trips at startup, during blower operation, or randomly. This helps identify the suspect component.
2. Visual inspection: With power off, inspect wiring to the blower, inducer, and control board for melted insulation or signs of arcing.
3. Isolate components (advanced): A technician can disconnect motors and test them individually for shorts to ground.
4. Do not upsize breaker: Never install a larger breaker to stop nuisance trips. The wiring and Thermia furnace are rated for a specific current.
5. Call a professional: Electrical shorts should be diagnosed and repaired by a qualified technician.

Furnace runs but trips the household circuit breaker intermittently.

Possible Causes