Furnace emits a burning smell when it runs

Safety: If you smell a strong electrical or plastic-burning odor, turn off power immediately and call a technician.

• 1. Initial season use: A mild burning-dust smell is common the first few cycles of the season. It should dissipate within an hour.
• 2. Clean furnace: With power off, vacuum dust from around the burners, heat exchanger, and blower compartment.
• 3. Inspect wiring: Look for discolored or melted insulation on wires. Do not operate the furnace if you see damage.
• 4. Professional inspection: Persistent or strong burning smells require a technician to inspect motors, wiring, and heat exchanger.