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March 21, 2023

If you have to plug your noise when your air conditioning is on, or find yourself trying to sniff out where that new odor is coming from, there may be something wrong with your home’s AC. Different smells may mean different things. If you are wondering, “Why does my AC stink?”, we review some of the most common reasons below.

Why Does my AC Stink?

If your AC is making your home smell funky, chances are, there is a reason, because your AC should generally not produce any noticeable smells. We review some of the odors you may be sniffing out, and reasons why you may be asking yourself, “Why does my AC stink”?

  • Musty or Moldy: If your AC smells musty or like mildew, moisture within your unit is probably the cause of the stench. If you smell a moldy odor, chances are that mildew or fungus has begun to grow in or near your air conditioner. This can come from various sources, so calling an AC professional is your best bet to resolve the issue. Exposure to damp and moldy environments can cause a variety of health effects, or none at all, depending on the person, and the amount of mold in the environment. You won’t want to leave the smell unattended for too long, as it is not only less than enjoyable, it could be impacting your home’s indoor air quality.
  • Exhaust Fumes: If your AC smells like an exhaust pipe, then you could have a refrigerant leak. These leaks can not only be dangerous to your health, but they can also shorten your HVAC system's lifespan. Air conditioners run on electricity, not fossil fuels, so an exhaust smell is a telltale sign that the fluids inside the motor or other components are leaking.
  • Rotten Eggs: If you are asking “Why does my AC stink?” and it’s because it smells like rotten eggs, you are likely looking for a solution to resolve the bad stench as soon as possible. This odor can be caused by a number of things, including a decaying animal within your ducts or a gas leak. If you smell this unpleasant odor, it’s best to leave the investigating and troubleshooting to the professionals. Open your windows and call a Marin, Sonoma, and Napa County HVAC expert right away.
  • Burning or Smoky: When your AC is on, does it smell like something is burning? If so, chances are that something is. A smoky or burning aroma coming from your air conditioner can be caused by dust burning off (this should go away after a while and is nothing to worry about), having a clogged air filter, a broken capacitor, your motor overheating, electrical components burning, or more. If the burning odor doesn’t go away after a while, turn off your HVAC system and call a professional.


Any time that you have to ask yourself, “Why does my AC stink?”, you should be alert and pay attention to what you are smelling. Sometimes what you are sniffing out can be easily explained and resolved, other times, the odors are an indication to much larger problems within your HVAC system.

Bragg Cooling, Heating & Plumbing is here for all of your Marin, Sonoma, and Napa County HVAC needs. When it comes to your comfort, you deserve the best solutions at the best value. All of our technicians and installers are Bragg employees dedicated to providing you with personalized solutions that meet your goals and budget.

HVAC problems can happen at any time and often require immediate attention. We’re available to provide fast same-day service throughout Marin, Sonoma, and Napa Counties at no extra charge. Contact us today.


July 12, 2022

No one wants to deal with a comfort system that is showing signs of inefficiency or having recurring issues. If you have noticed that your AC is not performing as it should and blowing warm air, making new noises, doesn’t work at all, or has another issue, you don’t want you and your family to be without cool air for too long. You should know the signs that an issue may be looming and be aware of the most common AC problems many North Bay Area homeowners face. Let’s review.

What are the Most Common AC Problems?

You don’t need to be an air conditioner or HVAC expert to know when something is wrong with your cooling system. There are common AC problems you could face that are usually easy to identify on your own; however, the fix, may require calling in a North Bay Area cooling expert. Below we take a look at some of the most frequent issues we see.

  • AC Will Not Kick On: One of the most obvious issues you could have with your air conditioning is that it will not turn on at all. Maybe it kicked on when you initially started it and now will not come on, or if it wouldn’t start at all, either way, if it’s not working, there is a problem of some sort. The hindrance could be as simple as your thermostat not being set to a low enough temperature, needing new batteries, not being set to AC, or maybe needing to be replaced all together. If you can’t find an issue with your thermostat, contact a local AC repair professional to help you diagnose and resolve the problem.
  • New Noises: Your air conditioning should never be making noises that are louder than a hum. If you notice a hissing, clicking, thumping or rattling, screeching, or buzzing, that is not normal, and there is an issue. If your AC is making sounds, it is trying to tell you something, so don’t ignore it. The new noises could indicate that there is a refrigerant leak, blower or motor issue, the condenser fan motor has a problem, there are loose parts, there’s an electrical issue, or more.
  • Unpleasant Odors: Much like you should listen for signs of an issue with your AC, you should also keep your other senses alert. If you smell something burning when your AC is on, there could be an electrical issue, the air filters could be dirty and blocked, or there could be another issue. If you notice a musty smell, there could be mold or mildew built up in your unit caused by improper drainage or another source. You won’t want to leave the smell unattended for too long, as it is not only less than enjoyable, it could be impacting your home’s indoor air quality.
  • Leaking Liquid: Again with your senses, keep your eyes peeled for signs of an AC problem. It’s usually rather easy to spot when you have liquid somewhere in your home, where it shouldn’t be; however, an AC refrigerant leak may appear within the unit, so it’s not super easy to detect. If you notice colored stains or liquid near your air conditioner, you likely have an issue. While it is okay to see some condensation on the outside of the unit, there should never be excessive moisture or colored stains.
  • No Cold Air: Another common AC problem people face is when they hear their AC running, but don’t feel any air coming out, or the air is warmer than usual. If your air conditioning is blowing warm air, there is a reason, and some are easier than others to identify and fix. As mentioned above, check your thermostat for any issues and make sure you have clean unobstructed air filters. If both your thermostat and air filters are in good condition, there could be an issue with your condenser, refrigerant, air ducts, or something else.


The majority of common AC problems are caused by a lack of maintenance. Dirty air filters, in particular, are to blame for a number of issues, including frozen evaporator coils and the blower motor overheating.

AC routine maintenance is the most important investment you can make for your air conditioning system. This not only includes replacing the air filter every 1 to 3 months, but it should also include professional inspections and tune ups as well.

At Bragg Plumbing Heating & Cooling we can help. If you are having trouble with your air conditioner, don’t hesitate to contact our Marin, Sonoma, and Napa County AC repair technicians for professional troubleshooting. We will take the time to explain what’s causing your cooling problem and discuss your options for repair.

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