Updated: April 2024

Unusual odors from AC systems are some of the most common HVAC issues for homeowners in Murrieta and nearby areas of southern California. Most smells from AC units can be easily fixed, but you should not ignore the problem. We Care Plumbing, Heating, and Air helps homeowners determine the source of the offensive smell and provides expert services to keep your home fresh and cool.

Here are some of the more common odors that come from air conditioning systems, and steps that you can take to troubleshoot on your own. You can also call We Care Plumbing, Heating, and Air to schedule an appointment with one of our technicians.

1. Dusty and Dry

A dusty and dry smell from your AC system is normal when you use it for the first time after the winter. The smell comes from the dust that has accumulated within the outdoor unit. Let it run, and give the system a few minutes to clear out the dust. You may also want to check your filters to see if they need to be replaced.

2. Stale Odor

Do you have a stale odor coming from your air conditioner? This is not normal and indicates that something is wrong. Stale odors most often come from old filters. Replace the filters, and see if it fixes the problem. If it doesn’t, check around the outside unit to see if there is any debris around it. Also, check for signs of pests. Little critters may have built a nest inside the unit or your ducts.

3. Rotten Egg Smell

We are all familiar with the smell of rotten eggs and sulfur. The aroma burns your nose and throat, and you just can’t seem to get away from the smell fast enough. Unfortunately, the primary reason why homeowners notice a rotten egg smell from the AC system is that rodents have gotten inside it during the winter and met a very sad demise. The carcass needs to be removed from the unit or ducts by a professional exterminator. If the smell persists after the animal is removed, call We Care Plumbing, Heating, and Air. We can come by to clean your ducts.

4. Musty

An AC system that emits a musty smell tells you that mold and mildew are growing somewhere within the system. The most likely places to look for mold and mildew are the drip lines and drain pans outside your home. Water can also accumulate inside the ducts. Be sure to check around the unit and on its walls, as many leaks are a bit more hidden from plain view. If you do find a leak, call the experts at We Care Plumbing, Heating, and Air. We will fix the problem and check the rest of the HVAC equipment.

5. Mr. Skunk

Another smell that we are all very familiar with is from a skunk. You should check your property first for any striped critters, and watch for any of its babies. Momma is never far away, and skunks can be very territorial when it comes to their youngsters. If you find no signs of the animals, the issue may be coming from your AC system. A skunk smell is similar to a smell often caused by a natural gas leak. Turn off the supply right away, and call the gas company who will send someone over to take a look.

6. Garbage Heap

Does your AC system smell like garbage? Chances are, that is exactly the cause. If you store your garbage bin near the outside unit, move it away to an isolated area. Check around the unit to see if there is any other type of foul-smelling debris that may have been carried in by the wind. This is also a great time to check for ants, rodents, and other pests that may have been attracted by the garbage.

7. Burning

The smell of burning can mean a few things during the summer. With changes to weather patterns, fires are more common. People are also barbecuing more during this time of year. Go outside and see if you notice the smell there. Look for smoke from your neighbors’ yards and large areas of natural forest or vegetation. If the smell is only indoors, the problem is most likely a failure of the electrical components of your AC. The smell may also be coming from melting plastic. Electrical issues should not be remedied by the average homeowner. Instead, turn off the system right away, and call the professionals at We Care Plumbing, Heating, and Air. Electrical shorts and malfunctions can lead to fires, so we will send someone over right away.

8. Exhaust Fumes

AC systems run on electricity, so you don’t expect to smell fumes, like what comes from a car’s exhaust system. When this type of smell is present in a southern California home, we often find that some of the liquids of the system are leaking onto warm components. The most common place for this type of problem is the refrigerant line. Turn off the system, and call us to schedule an appointment with one of our expert technicians. We will locate the problem and make the necessary repairs to keep your family safe and comfortable.

9. Smoke and Cooking Odors

If you smell an odor coming from your AC system that seems vaguely familiar, ask yourself if it might be cooking odors or tobacco smoke. The odor may be combined with dust, so it may not smell exactly like last night’s dinner, but close. If you notice these types of odors in your home on a regular basis, it may be time to install an air purification system from We Care Plumbing, Heating, and Air. The units not only remove odors, but also dust, pollen, mold, bacteria, viruses, and other harmful airborne particles.

10. Wet Dog Odor

We all love our pets, but not so much the odors that come from them after playing in the water and rolling around in dirt and mud. A “wet dog” smell typically indicates that a dog is nestled up against the outdoor unit or indoor air intake vents. It may also be a piece of damp clothing, towel, or another item. Check around the intake vents throughout your home and outside near the unit. If you find some wet or damp item, remove it and also check for mold or other issues. You may want to spray the area with a disinfectant to prevent any new problems.

Have an Odor From Your AC System?

If your AC system is emitting an odor instead of just cool, clean, fresh air, the experts at We Care Plumbing, Heating, and Air can help. We offer installation, repair, and maintenance services for HVAC systems, as well as indoor air quality products. Call us today to learn more. Be sure to ask about our plumbing services for new construction, remodeling, fixture repairs, sump pumps, and more.

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Author Bio: Rusty Cochran

Rusty Cochran - President of We Care Plumbing, Heating and Air ConditioningRusty Cochran is the President of We Care Plumbing, Heating and Air Conditioning. We Care began humbly, operating in his family’s living room. Under Rusty’s strong leadership, We Care has grown from 2 employees to over 200 employees. We Care Plumbing, Heating and Air has gained recognition across the HVAC industry, receiving numerous awards and certifications, including being named the ACCA Contractor of the Year, The Map Presidential Award several times, Angie’s List Super Service Award, NATE certification, and multiple Dave Lennox Awards. LinkedIn Profile

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