When turning on their furnace for the first time this season, many homeowners have reported a burning smell. This is perfectly normal and shouldn’t be considered as a reason for concern.
Over the summer, dust accumulates on heat exchangers and in ductwork, which then burns upon firing up their heater, resulting in that characteristic plastic burning smell.
Curious about a burning smell from your central heating system? Uncover the reasons and solutions with expert guidance from Anderson Air.
Dust
As their furnace and heat exchangers remain dormant for most of the year, homeowners often accumulate dust when turning their systems back on. When first powered up, this dust may ignite, giving off an unpleasant burning smell; however, this should dissipate within an hour after getting operational again.
For example, dust could collect in the blower motor causing it to smell bad upon starting up.
Dirty air filter
Burning smells coming from your heater may be caused by dust buildup in your air filter, but it should clear within an hour as the dust burns off. If it persists beyond this period, however, it could be down to an air filter with too much dirt, forcing your blower motor to work harder and causing higher electric bills as it consumes additional energy than necessary.
Depending on how severe this odor is, it may be wise to contact a professional heating technician and have their air filter changed or have their ductwork professionally cleaned to improve indoor air quality and avoid this kind of smell upon turning on your heater again.
Electrical issues
If other issues accompany the smell of burning plastic, switch off your heater immediately and shut the vent responsible. From there, you should be able to visually inspect for objects that may have entered vents or ductwork–possibly objects made from plastic, such as children’s toys–which might then start burning, producing an unpleasant odor as they begin burning off.
Burned plastic could also signal electrical wiring problems in your HVAC system, as exposed heat could cause it to burn away its insulation coating, creating a serious fire hazard. A professional HVAC technician should be able to test and replace damaged wires before they cause further harm or cause an electrical fire.
When should you be concerned?
While a burning smell is normal, if the smell is accompanied by smoke or sparks, shut off your system and contact an HVAC technician immediately. This could indicate that your furnace has malfunctioned and emits toxic gasses like carbon monoxide into the atmosphere.
Also, if you notice that the burning smell does not disappear but persists for a day or two, contact a professional as there may be something wrong with your unit.
Tips to minimize the smell and prevent damage
Here are some things you can do to minimize the initial smell and avoid damage to your unit.
- Store combustible materials away from HVAC units, such as bicycles or cardboard boxes, and change out filters regularly.
- Check your air filter regularly. Replacing your filter may help alleviate odor issues from burning fuel sources. Check it during off season to see if there’s dust accumulation.
- Schedule regular heater maintenance visits where technicians can replace filters and ensure all heating elements function as they should. Check up on your furnace in the summertime to prevent issues later on.
Overall, your system is important and with the best care it can keep you comfortable for years to come.
