Furnace starts but shuts down when blower starts; lights dim briefly.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Electrical safety: If lights dim significantly or breakers trip, avoid repeated restarts and call a professional.
Homeowner checks:
- 1. Inspect blower wheel: With power off, ensure the blower wheel spins freely and is not obstructed.
- 2. Check for overheating: Smell near the blower motor for burnt odor. If present, do not run the furnace.
- 3. Verify filter and vents: Ensure airflow is not restricted, which can increase motor load.
When to call a professional: A technician should measure motor amperage, check supply voltage, and replace the blower motor or capacitor with Philco-compatible parts if necessary.