If your home smells like rotten eggs, frayed wire, paint thinner, or sewage, you came to the right place! The strange, unpleasant smells invading your home may be the result of issues with your A/C. If this is the case, don’t panic. This blog contains simple DIY fixes for stinky A/Cs, plus how to know when it’s time to call a professional.

Different smells indicate different issues with your HVAC system, ranging from a dirty air filter to more serious problems, like a potential gas leak. Identifying these smells can help you uncover the most likely culprit of the problem and determine the urgency — so you can either tackle it yourself or know when to bring in a professional. 

What’s That Smell?

1. Musty Odor

Must typically indicates that mold or mildew is present in your HVAC system, typically in the evaporator coils or air ducts, as the result of moisture buildup.

What to do:

If your home smells more musty than usual, make sure to check the air filter and replace it if it’s dirty. Cleaning the evaporator coils and the drip pan is also important. 

To prevent mold from becoming an ongoing issue, consider using a dehumidifier to reduce moisture and clean any visible mold in accessible areas of the ductwork. 

When to call a Professional: 

If the musty smell persists after cleaning, or if you suspect mold is growing in areas that are hard to reach, like deep within the ductwork, it’s advisable to contact a Brea/OC Plumbing, Heating, and Air Conditioning professional.

2. Burning Smell

Burning smells usually signal an electrical problem. This might mean that components are overheating, there’s an issue with the motor, or debris is present in the system. 

What to do:

To prevent further damage, turn off the A/C immediately. Once the unit is off, inspect the area around the unit for visible debris and remove it, if safe. Also, ensure that the air filter is clean and correctly installed. 

When to call a professional:

If the burning odor continues even after you’ve cleaned the unit, or if you hear strange rattling noises, it’s important to call a Brea/OC Plumbing, Heating, and Air Conditioning professional, as this could indicate a significant electrical issue.

3. Sulfur or Rotten Egg Smell

If you smell sulfur or rotten eggs, this is a serious concern and could point to a gas leak or a dead animal within the system. 

What to do:

First, to turn off the gas supply and evacuate the area immediately. If you think the smell might be due to a dead animal rather than a gas leak, check easy-to-access areas in the ducts or the outdoor unit. 

When to call a professional:

If there’s a gas leak, contact your gas provider and an HVAC technician right away. If you’re unable to locate or safely remove a dead animal, it’s best to have a Brea/OC Plumbing, Heating, and Air Conditioning professional clean and sanitize the system.

4. Chemical or Paint Thinner Smell

If you notice a strong chemical odor, similar to paint thinner or industrial fumes, your A/C migh be experiencing a refrigerant leak. 

What to do:

If this is the case, turn off the A/C to stop any further leakage and ventilate your home by opening doors and windows. 

When to call a professional:

Refrigerant leaks are dangerous and require immediate attention from a Brea/OC Plumbing, Heating, and Air Conditioning professional who can repair the leak and recharge the system.

5. Exhaust Fumes

If your home smells like exhaust, there may be a fluid leak inside your A/C system.

What to do:

To prevent any further damage, turn off the A/C immediately. Inspect the unit for any visible leaks, especially if your system is older. 

When to call a professional:

If the exhaust smell persists or if you’re unable to identify the source, this may indicate a serious issue that requires the expertise of a Brea/OC Plumbing, Heating, and Air Conditioning professional.

6. Sewage Smell

A sewage smell might be the result of a backed-up drain line. 

What to do:

If you feel comfortable doing so, inspect and clean the condensate drain line, and ensure that all plumbing vents are clear. 

When to call a professional:

If the odor remains after cleaning the drain line, or if you suspect a more complex plumbing issue, it’s wise to call a professional technician to address the problem.

Conclusion

Enjoy fresher, cleaner air. If your A/C is producing strange smells, and you don’t feel comfortable fixing it yourself, contact a Brea/OC Plumbing, Heating, and Air Conditioning professional technician today.