Nine Suspicious AC Smells and What They Mean

Air conditioning is an important part of modern living, particularly during steamy summer months. When you turn on your air conditioner, you expect pleasant, cool, refreshing air to flow into your home. But occasionally, AC units produce odd or concerning odors that make you wonder if something’s wrong.

A strange smell generating from your AC unit or ductwork might be no big deal — or it could signal a severe problem requiring immediate attention. When you have concerns, turn off the unit and call an HVAC technician to look a little more closely. Right now, read about nine weird AC smells and what they might mean.

1. Rotten Eggs

A rotten egg smell could suggest a gas leak in your HVAC system. Air conditioners don’t function on natural gas, but they share a blower and ductwork with gas-fired furnaces, which could be the true culprit for this smell. If you detect a rotten egg smell emitting from the vents, turn off your air conditioner ASAP, open the windows for venting and evacuate the house. After that, call an HVAC contractor right away to check for a gas leak and complete the necessary repairs.

2. Musty Odors

A musty smell usually indicates mold or mildew growing inside the AC unit or ductwork. These microorganisms flourish in damp, dark conditions, making the evaporator coil and air filter well-known places for mold to develop. To get rid of the musty smell and prevent further mold growth, hire a specialist 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, chances 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 circulates into your home every time the air conditioner turns on. Change the filter plan routine maintenance to help prevent this AC odor. Also, it would be a good idea to not smoke inside the house.

4. Sewage 

If you notice a sewage smell from your air conditioner, your plumbing or sewer system is likely to be the issue. The smell may be created by methane gas emitting from a broken or plugged sewer pipe or a dry drain trap, which has managed its way into the ductwork. Methane is hazardous, so if you smell a sewage-like AC scent, contact a plumber immediately.

5. Stinky Feet 

A nasty air conditioner with a buildup of bacteria and fungi can emit a smell reminiscent of dirty socks. This odor may be especially strong when you turn on the AC for the first time of the season. Regular cleaning and maintenance aids to prevent this odor from developing.

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 not uncommon to find that a sick or injured bird, rodent or other pest climbed inside an air duct over the winter, where it died and began decaying. This is a health hazard, so reach out to an HVAC technician to tackle the problem.

7. Electrical Burning or Gun Powder

If your AC emits a burning smell, it’s likely due to an electrical issue, such as a damaged motor, circuit board, compressor or wiring. If any of these parts overheat, they may emit a burnt, gun powder-like smell. To protect against long-lasting damage, turn off the AC now and get in touch with an HVAC technician to diagnose and fix the issue.

8. Car Exhaust

A smell identical 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 significant health and environmental hazard, so switch off your cooling system and call for help.

9. Chemical Fumes

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

Schedule Air Conditioning Repair

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

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