Bad Air Conditioner Unit Smells & What To Do

Published On: November 14, 20220 Comments on Bad Air Conditioner Unit Smells & What To DoTags: Last Updated: January 29, 20245.5 min read

Many people do not understand how much their air conditioner impacts indoor air quality until something goes bad. While preventing air conditioning problems through active maintenance culture is best, some problems may creep up on you. Are you experiencing weird and strange smells in your home? There’s a chance that it may be from your air conditioning unit.

bad smell from AC

Here are the nine bad smells your air conditioning unit can produce and advice from a heating and cooling company on what to do.

Rotten Egg Smell

Every homeowner can agree that this is probably the worst smell in your home. It’s neither manageable nor welcome. If your home has started smelling like a rotten egg, the chances are high that your air conditioner unit is the culprit (assuming you don’t have a rotten egg in the house). Addressing this problem as quickly as possible is essential, especially if you don’t want the stench to get on items like your couch, curtains, etc. Leaving this problem unattended creates a potential problem as your air conditioner may catch on fire, explode, or worse still, cause health problems due to reduced oxygen levels in your bloodstream.

Solution: Turn off the gas supply to eliminate this problem caused mainly by gas leaks in the ductwork. Once safely turned off, have everyone evacuate the building and call your HVAC technician, gas company, or 911.

Dirty Socks Smell

There’s that tangy and musky smell you can always associate with moist and dirty socks. If you come across this type of smell in your home, instinctively look for its source. You’re safer if there’s an actual dirty sock lying around. However, you should act fast if it’s your air conditioner unit. Although this smell is neither dangerous nor poses imminent danger, it reduces the air quality in your home.

Solution:  Dirty socks smell may be a problem from your unchanged or dirty air filter. Start by changing the air filter and watch how your indoor air quality improves dramatically. You can also contact your HVAC contractor for a cleaning and maintenance task to address additional issues that may cause this problem. Your AC technician will check the evaporator coil and drain as part of the task.

Musty Mildew Smell

The musty mildew smell is usually cold, moist, and heavy. You can always associate this smell with basements or old storage spaces. If your home begins to smell like this, chances are high that there’s an undetected moisture problem.

Solution: Check for the moisture source and address it immediately. Sometimes, it may be hard to identify the problem’s cause and may require professional help from an HVAC technician. Your technician will check the AC filter, condensate line, ductwork, and other areas to identify and solve the problem.

disinfecting indoor AC unit

Burning Smell

There’s that unmistakable aroma associated with burning substances. If you can perceive the burning smell from your air conditioner unit, the chances are high that an electrical malfunction has occurred within it. Sometimes, the burning smell may hint at bigger problems down the line. It would be best to address this as quickly as the smell registers.

Solution: Turn off your air conditioner unit immediately to prevent further damage or fire incident. Contact your HVAC contractor immediately for help. However, if you’re unsure whether the whiff came from the air conditioner, you can wait a few minutes while monitoring the unit. If the smell dissipates, you may have nothing to worry about.

Exhaust Fumes

Exhaust fumes in your home can be tricky and cause panic. It is often the first sign of a fire problem in the works. It would be best if you always acted fast to save your home from burning down. Once the exhaust fumes are noticed, turn off your power supply and wait for a professional.

Solution: Exhaust fumes are common signs of burning fossil fuels, which may indicate a refrigerant leak in this case. Turn off the system or your home’s power supply and wait for your HVAC contractor to arrive.

Vehicle Coolant

The vehicle coolant smell is tricky, especially for people unfamiliar with vehicles and their fluids. This smell is rather sweet due to the Freon or R-22 it contains. If you suddenly can perceive a sweet-smelling substance without using air fresheners, chances are high that your air conditioner is leaking freons into your home. It is important to note that although sweet-smelling, freons can be toxic and dangerous to the health.

Solution: Turn off your air conditioner quickly. Open your windows wide to allow the freon to dissipate into the surrounding environment. By diluting your indoor air, you reduce the chances of any fatal health damage. Contact your HVAC technician as quickly as you can.

Cigarette Smoke

Everybody has come in contact with a cigarette smoker at least once. The smell is different due to the nicotine contained in it. For most people, the smell is repulsive and can easily be picked up a few meters away. If you notice this kind of smell inside your home, there’s a chance that your air filter needs help.

Solution: This problem may become common among indoor smokers whose air filters have become clogged with the smell from trying to recycle the indoor air. Contact your HVAC technician for a new air conditioner filter. Ensure that indoor smoking is also reduced or eliminated.

Skunk Smell

If it’s strong and repulsive like a skunk’s smell, it’s probably a skunk. Skunks are notorious creatures and may have angrily sprayed your Air Conditioner’s outdoor unit. The smell transfers from the outdoor unit into your indoor space and may give you a bit of a kicker.

Solution: This problem can be tricky, especially because of the skunk smell. Turn off your air conditioning unit to prevent further circulation. Open windows and doors to let the smell out, and contact your HVAC technician for a clean-up and maintenance appointment.

Garbage Smell

Unlike the other smells, garbage has a distinct smell, probably due to its decaying materials. When this smell hits, the chances are high that you have dead organic matter like birds, raccoons, rodents, or other critters around or in your ductwork.

Solution: You’ll need a cleaning company to trace the smell and remove the dead matter. The company should also handle disinfection and decontamination of the area.

These common smells should not be ignored for safety and health reasons. If you have any problems with them, contact the nearest HVAC technician for help.

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