Why is My HVAC Unit Causing a Smell?

“Why is my HVAC unit causing a smell?”This time of year, it’s a question we hear at MTB Mechanical a lot. The good news is, it’s not always cause for concern! A little bit of odor from your air treatment system is normal, but there are a few signs to look for that something might be wrong.
Common HVAC Smells and What They Mean
Heating systems very often smell like burning when they’re first turned on for the season. As long as the smell doesn’t persist past the first few minutes of use, it’s not really anything to worry about. Air conditioners are a different matter. In general, your AC unit shouldn’t produce a smell if it’s working properly. Common AC smell complaints include:
Musty Smell: A musty or “moldy” smell is likely the result of condensation within the unit that’s not draining off properly. That moisture can cause mold to build up in the ducts or vents; turning on the unit pushes these particulates out into the air of your home.
Gas Smell: The smell of natural gas – often described as a “rotten egg” smell – can indicate a serious leak inside your HVAC system. Immediately turn off the system, leave your home, and call the gas company if you notice this kind of odor.
Dusty Smell: If you smell an odor similar to the one you notice when your heat is first turned on coming from your HVAC system, it might be dust. If the smell doesn’t dissipate or come directly from the vents, you could have a leak at a pipe fitting.
Rotting Smell: As unpleasant as it sounds, animals sometimes find their way into air ducts and begin to decay. Although this condition isn’t dangerous, it’s pretty unsettling; call an HVAC repair company right away to have it taken care of.
Burning: Although your HVAC system might create a dusty smell as dust from lack of use “burns” off, your HVAC system shouldn’t smell like something’s actually burning. This could indicate a mechanical problem, so turn off the system and call in a professional.
How to Fix an HVAC Odor
Today’s homes are often built too tightly, meaning they don’t have enough ventilation to allow normal smells to escape. An HVAC professional can help determine whether or not your ventilation is adequate. Be sure you’re also changing your air filters frequently – dirty filters can result in unpleasant odors vented throughout your home!
The best thing to do if you notice an odor coming from your HVAC system is to call in a professional immediately. A trained HVAC technician can inspect your equipment and cooling components to ensure they’re all in working order and that nothing is malfunctioning. They can also clean your ductwork and vents, creating a clear network for conditioned air to move through.
Does your air conditioner smell? MTB Mechanical can help. Give our experienced crew a call today for a complete inspection and cleaning.