Check the area around your furnace
Make sure combustibles are away from the furnace, if you have a natural gas furnace. This includes keeping boxes and flammable items cleared around the unit. For those who have an all electric system or heat pump, then those precautions aren’t as relevant since there is no combustion.
Check your air filters
Always put a new filter in at the start of the season before turning system on so you get good airflow and filter the particulates.
Check your attic vents
If you have had some roofing done on your home recently, check to make sure the flue/exhaust pipe was not damaged or moved. It’s very common for this to happen after work is done on a roof.
What is that smell?
Smelling something burning is not something to worry about, because your furnace can gather dust over the spring and summer. As your furnace ignites to start heating, the dirt and dust burns off, flowing through the ductwork and eventually into your home. This smell typically goes away in a few minutes to a few hours.
Fire alarms
Red lighton furnance in attic and check for the red light,