Furnace emits a burning dust smell when it starts, especially at the beginning of the heating season.

Safety first: If the smell is strong, acrid, or accompanied by smoke, turn off the furnace and investigate immediately.

• 1. Initial seasonal burn-off: A mild burning dust smell for the first few cycles of the season is common as dust burns off the Thermia heat exchanger. This should dissipate quickly.
• 2. Clean furnace interior: With power off, remove access panels and gently vacuum dust from around the burners, heat exchanger surfaces, and blower compartment. Do not disturb wiring or gas components.
• 3. Replace filter: Install a clean air filter to reduce dust accumulation.
• 4. Persistent odor: If the smell continues or worsens, have a technician inspect for electrical overheating or soot.