Dettson furnace emits a burning smell when it runs.

Safety first: If you smell a strong electrical or plastic burning odor, turn off power immediately and inspect for damage.

• 1. Initial seasonal odor: A mild burning dust smell is common the first few cycles of the season. It should dissipate within an hour of run time.
• 2. Clean interior: With power off, vacuum dust from around the burners, heat exchanger surfaces, and blower compartment.
• 3. Inspect wiring: Look for discolored or melted insulation near the burners or on the control board. Replace damaged wiring and correct the cause.
• 4. Remove foreign objects: Ensure no plastic, insulation, or debris is touching the heat exchanger or flue pipe.
• 5. Persistent strong odor: If the smell continues or worsens, have a technician inspect for overheating motors or electrical faults.