May 14, 2021
Dirty AC Unit in Northern California

Many people use their air conditioning units to cool their living spaces as the weather outside warms up. Therefore, you need to ensure your AC system is working well before the onset of the hot summer months. One of the problems you might notice once you switch on your AC for the first time is unpleasant odors coming from the system. Several causes might be the main culprit, and knowing the exact reason why your air conditioning system is emitting funny smells can help you determine how to eliminate them. Below are common AC odors, what each means, and how to eradicate each of them.

1. Musty Odor

If you notice an unpleasant, spongy, and lingering odor each time you turn on your system, there might be an issue with your drain duct. Your air conditioner’s drainage system collects all the condensed water drops and removes them from the unit. If the excess moisture does not drain completely, it’ll build up in the drain line. This can promote the growth of mold, mildew, and other bacteria inside or somewhere near your unit. The microbial growths will cause your AC system to produce a musty odor, which can cause severe respiratory complications.

Standing water in the AC unit’s drain pan, a dirty filter, leaks in your ducts, or clogged drain lines can all create a musty smell that permeates through your home’s air vents. Have an AC technician inspect and clean your unit to eliminate the foul odor.

2. Stinky Feet Smell

You may notice a stinky feet smell when you first switch your system on at the beginning of the warm season. After a long period of inactivity, bacteria and mold can accumulate on your evaporator coils or other parts of your air conditioning system. A clogged filter or the accumulation of old and dirty water in the unit can also cause this funny odor.

Your system will need a thorough professional cleaning to get rid of this awful smell. The AC expert will check the system for any drainage problems before cleaning your evaporator coils and sanitizing your condenser. Regular maintenance checks and servicing the unit before the onset of the warm months can prevent this problem.

3. Oil Odors

Another odor to watch out for from your air conditioning unit is an oily smell. This smell can have several causes, and some might be minor concerns while others might indicate major problems. Regardless of the case, you need to address these problems immediately to avoid further damage to your HVAC unit. One of the common causes of oily odors is an oil leak, which often requires tightening some valves. The odor could also mean the burner has clogs, which can be dangerous if not fixed immediately.

4. Rotten Eggs Odor

One of the main causes of this smell is pest invasion. Birds, rodents, and other critters can climb into your AC ductwork to shelter against the harsh weather during the winter season. Sometimes these creatures might die inside the unit and begin decomposing, which results in an acrid smell. To eliminate this odor, have your ductwork checked by an AC expert and professionally cleaned. You can also prevent critters from accessing your HVAC unit by pest-proofing your home.

5. Sewer Smell

If a sewer line ruptures or backs up near your air conditioner’s duct system, you might notice a sewer odor in your home. What you smell is methane gas emitted by the sewer circulating in your ducts and being blown all over your living space. If not addressed in time, this can lead to sewer backups in your residential property and serious health risks. Contact your plumbing contractor immediately to check and repair your sewer system.

6. Burning Odors

An AC burning smell is similar to gunpowder odor and can point to malfunctioning or damaged electrical components. If some parts within your unit malfunction, they can cause your motor to overheat or the wires’ insulation to melt. The burning smell can also indicate a circuit board short or mechanical failure.

Other causes of AC burning odors might be a dirty filter causing your system to overheat. A faulty fan motor might also produce this smell.

7. Acetone Smell

Acetone odor is similar to the strong smell of nail polish remover. It can originate from your ductless mini-split systems, heat pump, or air conditioner when there is a refrigerant leak. In many cases, refrigerant leaks are usually accompanied by decreased temperature control. Therefore, you should allow an AC professional to handle the issue to avoid further damage and ensure proper disposal.

8. Gas or Skunk Odor

A “skunky” smell coming from your AC may indicate a gas leak somewhere near your unit. The gas companies put an additive known as methyl mercaptan in the gas to produce this unmistakable smell when there’s a gas leak in your residence. The smell can enter your ductwork and circulate throughout your house. Since gas leaks are dangerous, open all your doors and windows and exit the house before calling your gas company to fix the issue.

9. Old Cigarette Smell

The odor of stale cigarette smoke originating from your air conditioning vents can be quite unpleasant. It simply means that the air filters and condenser coils have absorbed old tobacco smoke. If you are a heavy smoker or you have one in your family, it’s important to have regular maintenance checks to prevent smoke residue on the coils.

If you are a cigarette smoker yourself, you are unlikely to notice this smell from your AC. However, if a non-smoker purchases a home from a heavy smoker, the odor is pretty obvious. Fortunately, a filter replacement and professional cleaning of the unit are all you need to remove old cigarette odor from your home’s AC vents.

Partner With an HVAC Specialist

Air conditioning units recycle the air inside your home to make it feel cool and refreshing. Therefore, any foul odor coming from your unit could cause concern, and having it checked is the best option. That’s because unpleasant AC smells can have a direct impact on your family members’ moods and even their health. Furthermore, ignoring the odor problems can also lead to expensive AC repairs or replacements.

The best way to prevent air conditioning odors is professional maintenance. With HVAC maintenance, a trained AC contractor can perform a comprehensive inspection to check all the system parts and clean them to prevent foul odors. And you will enjoy better indoor air quality and increased efficiency to boot. If you reside in Sacramento, CA, and need assistance getting rid of any of the above nasty odors, contact a professional from Gallagher's Plumbing, Heating and Air Conditioning today. Our team of experienced experts can answer any questions you have and perform the necessary repairs and cleaning to make your house smell fresh when your air conditioning system is running.

Apart from AC-related services, we also offer heating, air quality, and plumbing services. If you would like to try any of our services, contact us now to schedule an appointment.

company icon
Categories: