09/07/2026
That smell the first time the heat comes on is dust burning off the heat exchanger. It sat there all summer, the burners fire for the first time since March, and it cooks off.
It should fade within an hour or so. If it lingers past that, or smells sharp rather than dusty, turn the system off and call someone. Burning dust is normal. Anything electrical or acrid is not.
First cold night usually lands mid-October around here. Now you know what it is.