HVAC smells run the gamut from the insignificant to the urgent. As system airflow circulates throughout the house in ductwork, HVAC smells may appear to be coming from everywhere. They will no doubt get your attention, and in some cases, they may require taking prompt action to deal with a potentially hazardous emergency. In other cases, however, the odors will dissipate rapidly and are not a concern.
From the harmless causes up to the most hazardous, here’s a rundown of what a variety of typical HVAC smells indicate:
The smell of paper burning.
This is often a sharp, acrid odor emitted by the furnace when the unit is first started up for the season. Over the offseason, dust typically accumulates on furnace burners. At seasonal start-up, this dust burns off and produces an odor that smells like paper burning. This odor should dissipate within the first day of operation. If it persists longer, shut off the furnace and contact your HVAC contractor.
A musty smell.
This refers to wet, “swampy” odors emanating from ducts. Usually, it means mold or mildew growing somewhere in the system. Typical causes are ductwork that has been infiltrated by water from some source, such as a roof leak into the attic. Another common source of HVAC smells due to mold or mildew is the central air conditioner’s condensate drip pan located under the indoor air handler.
The smell of hot electrical wiring.
When it’s noticeable every time the system cycles on, these HVAC smells likely indicate a damaged blower motor or other electrical component that is overheating. Shut down the system at the thermostat and call for professional service.
A smell like rotten eggs.
This is the classic odor given off by natural gas. It is a critical danger when inhaled, as well as a severe fire hazard. If the odor emanates from HVAC vents, it’s probably originating at the gas furnace. Shut down the furnace immediately and get everyone out of the house. Then call your local gas company for advice.
To clear the air of HVAC smells in your home, contact the professionals at Energy 1 Heating & Air Conditioning.
Energy 1 Heating & Air Conditioning
1 (440) 246-5440
Serving the Lorain, OH Area