Nine Strange AC Odors and What They Mean

Air conditioning is an essential part of modern indoor comfort, especially during steamy summer months. When you use your air conditioner, you anticipate wonderful, cool, refreshing air to flow into your home. But once in a while, AC units produce strange or concerning odors that make you curious if something’s wrong.

A strange smell coming from your cooling system or ductwork might be no big deal — or it could signal a serious problem that requires urgent attention. When you have a question, power down the unit and call an HVAC technician to check it out. Right now, find out about nine weird AC smells and what they might mean.

1. Rotten Eggs

A rotten egg smell could point to a gas leak in your HVAC system. Air conditioners don’t operate on natural gas, but they share a blower and ductwork with gas-fired furnaces, which could be the real reason for this smell. If you notice a rotten egg smell originating from the vents, turn off your air conditioner right away, open the windows for ventilation and evacuate the house. Then, call an HVAC contractor promptly to check for a gas leak and perform the necessary repairs.

2. Musty Odors

A musty smell commonly means mold or mildew growth inside the AC unit or ductwork. These microorganisms multiply in damp, dark spaces, making the evaporator coil and air filter prevalent places for mold to set in. To get rid of the musty smell and prevent further mold growth, hire a professional to clean your air conditioner, replace the filter and determine any other sources of moisture.

3. Tobacco Smoke

If an individual in your home smokes, odds are the AC will start smelling like a dirty ashtray before long. The buildup of nicotine and other chemicals inside the unit, air filter and ductwork enters into your home every time the air conditioner turns on. Change the filter on a regular basis routine maintenance to help minimize this AC odor. Also, it would be smart to not smoke inside the house.

4. Sewage 

If you detect a sewage smell from your air conditioner, your plumbing or sewer system could have a issue. The smell may be created by methane gas emitting from a broken or plugged sewer pipe or a dry drain trap, which has made its way into the ductwork. Methane is dangerous, so if you smell a sewage-like AC odor, contact a plumber without delay.

5. Stinky Feet 

A nasty air conditioner with a buildup of bacteria and fungi can emit a smell reminiscent of sweaty socks. This odor may be especially strong when you start up the AC for the first time of the season. Regular cleaning and maintenance helps prevent this odor from happening.

6. Skunk Smell

If you smell a skunk-like odor coming from your AC unit, there may be a decayed animal or animal poop inside the ductwork. It’s possible a sick or injured bird, rodent or other pest climbed inside an air duct during the winter, where it died and began decomposing. This is a health hazard, so contact an HVAC technician to tackle the problem.

7. Electrical Burning or Gun Powder

If your AC releases a burning smell, it’s possibly due to an electrical concern, such as a damaged motor, circuit board, compressor or wiring. If any of these parts overheat, they may produce a burnt, gun powder-like smell. To prevent permanent damage, turn off the AC now and contact an HVAC technician to diagnose and fix the issue.

8. Car Exhaust

A smell comparable to car exhaust could indicate a refrigerant leak. Refrigerant is the chemical your air conditioner utilizes to remove heat from the indoor air and exhaust it outside. A leak can be a major health and environmental hazard, so shut down your cooling system and call for help.

9. Chemical Fumes

A chemical-like smell originating from your air vents could be sourced to surrounding vehicles, cleaning products, paints, adhesives or other substances. If your AC blower fan motor is situated in the garage, even your vehicle’s idling exhaust could seep into the indoor air. These are grave concerns that could call for sealing the ductwork or even reworking your HVAC system.

Schedule Air Conditioning Repair

If you’re thinking about a weird smell arising from your air conditioner, consider Service Experts Heating, Air Conditioning & Plumbing for the repair you need. We use state-of-the-art diagnostic equipment to quickly and accurately define the problem. Then, we’ll explain the most cost-effective repair methods and present recommendations to prevent a recurrence. We believe in our quality work so much that we insure every repair with a one-year 100% satisfaction guarantee! Phone a Service Experts office near you for more information or to request air conditioning repair in the U.S..

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