Common Causes
- Overheating electrical components, including a failing motor, capacitor, or wiring
- Dust burning off a heating component the first time it runs after a period of disuse (typically brief and light, not a strong or lasting smell)
- An electrical short or overloaded circuit
- A failing blower motor bearing generating friction and heat
What You Can Safely Check
- Turn the system off immediately at the thermostat
- If the smell is strong, accompanied by smoke, or you have any safety concern, also turn off the breaker for the system if you can do so without touching any part of the panel beyond the breaker switch itself
- Do not turn the system back on to "see if it happens again"
When to Call NILOV
- Any burning smell that is more than a brief, light dust-burning smell on first seasonal startup
- Any burning smell accompanied by smoke, sparking, or visible damage
- Any burning smell that returns after the system is restarted
- Immediately, in all of the above cases — this is not a wait-and-see situation