How to Fix / Troubleshooting

Safety: If the smell is strong, plastic-like, or accompanied by smoke, turn off power immediately and do not use the furnace.

Initial burn-off: A mild dusty smell at first startup of the season can be normal and should dissipate after a short period.
Inspect interior: With power off, remove panels and look for melted insulation, discolored wiring, or foreign objects near the heat exchanger.
Check blower motor: Feel the blower motor housing after operation (careful, may be hot). Excessive heat or visible discoloration suggests motor issues.
Clean furnace: Vacuum dust from accessible surfaces without disturbing burner or control components.

Persistent burning odors require professional inspection to rule out electrical or heat exchanger problems.

Furnace emits a burning smell when running

Possible Causes