4 Unpleasant HVAC Odors (and Their Causes)

Everyone has experienced a few bad B.O. days and this even includes your HVAC system. However, when your HVAC produces an unpleasant odor, you can’t cover it up with deodorant and body spray. Unpleasant HVAC odors could signify a larger issue within your system. But what kind of smells should you look out for?

The experts at Iceberg Heating & Cooling have come up with a list of the types of smells your HVAC system can produce. Below are 4 unpleasant HVAC odors and their respective causes.

1. Rotten Odor

If your HVAC system is producing a rotten smell, this could mean a few things. First, if the smell is similar to rotten eggs, this could indicate a natural gas leak. Natural gas is a fuel source that can be used to power your HVAC system. If the fuel source begins to leak, a smell similar to rotten eggs is produced.

Fun fact: Natural gas is actually odorless. A chemical is added to the gas to give it the smell of rotten eggs. This is done to notify if a leak is present.

A rotten smell could also be from dead pests and rodents that had invaded your HVAC system. Mice, rats, and squirrels that died in your ventilation will begin to decompose and produce the smell of rotten flesh.

Regardless, you’ll want to get your HVAC system inspected as soon as possible if you notice a rotten smell.

2. Burning Odor

A burning smell is a common odor produced by your HVAC system.  When you first turn on your heater, there may be some dust lingering around the unit. This dust gets burned up by your heater, which produces a burning odor. Noticing a burning smell every time you turn on your heater could signify your filters need to be replaced.

However, more severe causes exist. An overheated motor or fan can produce a burning smell and may even emit smoke from your vents. If your HVAC system produces a burning smell that has not gone away, turn off your heater immediately. Contact Iceberg for further analysis on your heating.

3. Moldy Odor

Smells of mold occur when moisture build-up has been present for a while. When moisture has lingered in a dark area, mold growth and bacteria will begin to form. One cause of moisture build-up is a refrigerant leak. A refrigerant is a vital part of your A/C unit, as it converts vapor to liquid and vice versa. If it leaks, the liquid spills and can lead to mold growth.

Water that has leaked into your air ducts can lead to a moldy smell as well. Roof leakage, damaged ducts, and poor insulation can all leak water into your air ducts. If you notice a moldy smell, you’ll need to contact a professional to inspect your HVAC system.

4. Oil Odor

Oil is another fuel source for your HVAC system, and is common in colder regions – such as Michigan! When oil leaks, your HVAC system can carry the accompanied odor throughout your home. Oil can leak from your furnace or even the oil tank itself. A loose fitting or faulty part is usually the cause of the oil leak.

If there is no leaking oil around your furnace, then the problem may be the oil burner. Oil burners are used to heat the oil. Unfortunately, they are victim to clogs, damages, and a bad connection to the fuel pump, all of which can produce an oil odor.

For more info on oil furnaces, check out this article from the U.S. Department of Energy.

Unpleasant HVAC odors should be your first indicator to contact a professional. Contact Iceberg Heating & Cooling today for affordable maintenance services. We offer a full assessment of your HVAC system and can determine a cost-effective solution for your Monroe home. Call us at 734-342-3420 to schedule an appointment and get started!