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Why Does My Air Conditioning Smell: Causes and Solutions

Cassie Pound, owner of Quality Heating, Cooling, Plumbing & Electric
Published by
Cassie Pound
September 10, 2022
Why Does My Air Conditioning Smell: Causes and Solutions

If you are asking, “Why does my air conditioning smell?” you are in the right place to learn what could be causing it and the solutions to fix it—Call 918-212-0122 to reach the pros at Quality Heating, Cooling & Plumbing.

You depend on your air conditioner to keep you comfortable, but what do you do when your home cooling system begins to smell bad? 

Let’s dive into the seven most common causes and solutions for air conditioners that don’t smell quite right. Don’t worry; you don’t have to learn a new trade or attempt to DIY the repairs. You can depend on your experienced local heating and cooling contractor in Tulsa, OK

#1 Moldy or Mildewy Scent

A musty smell is a strong indicator of dirty filters in your air conditioner. Another possible cause for this scent is a build-up of moisture in the system from a clogged drain or another failing part.

If there is water lingering in your air conditioner, it can contribute to mold growth. Your air conditioner will also push out tiny, growing mold particles that will impact air quality and might promote more mold throughout your home. An issue like this can be significantly harmful to those with respiratory conditions.

In some cases, all you need to do is change or gently clean and dry your air conditioner’s air filter to eliminate this scent. If changing or cleaning the filter doesn’t stop the smell, you will need an expert HVAC technician to diagnose the unit and provide reliable and long-lasting repair services.

#2 Chemical Smell

If you are asking, “Why does my air conditioning smell like chemicals?” there are multiple potential causes. Check out this list of things to look for if your AC has a strange smell:

  • Open or leaking chemicals near intake vents or ducts: Check these areas for spilled cleaning products like bleach or ammonia.
  • Freon or other leaks within the air conditioning unit: Look for any signs of liquid in or around your AC unit. Freon often smells vaguely sweet, much like the coolant for your car’s engine.
  • Ozone-producing filters or UV sterilization in your AC: Take note if the AC airflow smells like chlorine. Watch for chest pains or unexpected issues with breathing, as these are common symptoms of breathing unhealthy air.
  • Recent ductwork can cause a strong glue odor: Open windows to help release the fumes from the adhesives. Turn on the AC fan until the smell goes away.

These variables can negatively affect indoor air quality, and some, like freon leaks, are incredibly toxic. If you smell chemicals while your AC is running, you should contact a professional to diagnose and repair the system completely to protect your health.

#3 Exhaust Fumes

Another one of the many unpleasant odors your AC might emit can include a smell that is similar to exhaust fumes. If you smell something similar to the fumes from an exhaust, you need to stop running the AC immediately.

The cause of this scent is often due to multiple leaking chemicals that are heating up and releasing unwanted and ultimately dangerous toxins into the air. The only way to safely fix your air conditioner is to call an experienced HVAC professional for diagnostics and repair or replacement.

#4 Rotten Eggs or Sulfur Smells

If you notice a bad smell that reminds you of rotten eggs or sulfur, there is a high chance of a gas leak in or near your home. Due to the highly flammable and explosive qualities of natural gases, you must shut off your gas line if possible and contact your local agencies immediately.

The agencies you should contact will typically include your utility or gas provider and the fire department. Some air conditioning and heating systems share the same air ducts, requiring the thorough attention of HVAC experts to complete the appropriate repairs for your system.

#5 Gunpowder Scents

If you are wondering, “Why does my air conditioning smell like gunpowder?” your AC might be experiencing one or more electrical failures. Burnt-out circuits or failing motors can give off this scent — particularly in older air conditioning systems that have been inactive for a prolonged time.

This unwanted AC scent can indicate a need for professional replacement of electrical components or a complete system replacement.

#6 Burnt or Burning Smell

You might wonder, “Why does my air conditioning smell like it’s burning when I begin using it each summer?” The most common answer is that the unit is heating up and burning off accumulated dust. If this scent stops after a few cycles, you don’t have to worry about it.

However, if the scent continues beyond a few cycles or gets stronger as the system runs, you might have a more complicated AC problem on your hands.

#7 Rotting Scent

The last common reason for a strange smell coming from your air conditioning could involve dead rodents or other pests. Some smaller animals are fond of using ventilation ducts as highways through your home, and occasionally, they will pass away in those vents.

In this situation, you may find that combining professional HVAC inspections and ventilation cleaning with pest control services will eliminate both the smell and the chances of it happening again.

Schedule an Appointment with Quality Heating, Cooling & Plumbing Today

Our team offers in-depth air conditioning services to Tulsa residents, including

  • Diagnostics and repair services
  • Maintenance
  • Professional installation

The answer to “Why does my air conditioning smell?” isn’t always a simple explanation or an easy repair that you can perform on your own. In most cases, you will need expert advice from a highly trained and state-certified HVAC technician to identify the exact issue in your air conditioning unit.

Do you know why it’s not a good idea to DIY your AC maintenance? You might be surprised by the answers we share. When you need professional AC services, call  918-212-0122 to schedule your appointment with Quality Heating, Cooling & Plumbing in Tulsa, OK.

Cassie Pound, owner of Quality Heating, Cooling, Plumbing & Electric
Published by
Cassie Pound

Cassie Pound is the Vice President of Quality Heating, Cooling, Plumbing & Electric with locations in Tulsa, Glenpool, and Bartlesville, Oklahoma.