A burning smell when you turn on your forced air heat is often due to one of the following reasons:

1. Dust Burn-off: After the heating system has been inactive for a while, dust can accumulate on the furnace’s heating elements or in the ductwork. When the system is turned on, this dust burns off, creating a burning smell. This is especially common at the start of the heating season. NADCA recommends to have your ducts cleaned every 3-5 years. 

2. Clogged Air Filters: Dirty air filters can cause the heating system to overheat by restricting airflow, which may result in a burning smell. Regularly cleaning or replacing filters can prevent this.

3. Electrical Issues: If you detect a persistent burning smell, it could indicate an electrical problem like overheating wires or malfunctioning components. In this case, it’s important to have a professional check the system to prevent potential fire hazards.

4. Furnace or Heater Malfunction: Overheating in the furnace’s motor, blower, or other components can cause a burning smell. This requires immediate attention to avoid further damage.

5. Debris in Ducts: Small items like debris, pet hair, or even insects can get into the ducts and burn when the heat is turned on.

If the smell doesn’t go away after a few uses or is particularly strong, it’s best to have the system inspected to rule out any dangerous issues. For expert inspections, choose Advanced Air Duct Cleaning. Reach out to get started.