5 Reasons Why Your HVAC System Stinks!

Every homeowner wants to have a comfortable, clean, and fresh-smelling environment inside their living space. If your home smells less than pleasant, the solution may not be as simple as spraying air freshener or lighting a scented candle. Unfortunately, a lasting foul odor in your home may be the result of an issue with your heating or cooling system.


Masking the smells with odor-eliminating techniques won’t fix the cause of the problem. Here are five of the most common causes for unpleasant, foul-smelling air coming from your home’s heating or cooling system, as well as some potential quick fixes.


1. It’s the first time you’ve used your heater this season.

It’s normal to notice a burning or smoky smell when running your furnace for the first time in several months. It only becomes an issue if the smell doesn’t go away after a few heating cycles. The smell is a result of all the dirt and dust that accumulated during the spring and summer months burning off.


If you notice the burning smell in the middle of the heating season, this may be a result of a clogged air filter. If your filter is clogged, it may cause dirt and dust to build up within your system, or it may lead to your system overheating. Be sure to shut the unit off and contact a heating expert for a professional inspection.


2. The air filter is clogged with dust and debris.


Heating and cooling experts cannot stress enough how important it is to change your air filter on a routine basis. If you’ve read our previous blog posts, you already know how often we remind our readers of this fact!


All air circulating through your home must pass through the filter in your furnace. Regardless of the time of year, air from your heating or cooling system passes through this filter. Replace the filter as often as is specified in your unit’s owner’s manual. A good rule of thumb is to swap the filter out at least once a month when your furnace and air conditioner are being used the most – e.g., the dead of winter and the dog days of summer.


Changing your filter often will improve your indoor air quality as air isn’t trying to pass through a dirty, dusty filter. If it’s been a while since you’ve replaced your filter, and your home isn’t smelling fresh, this may be the answer.


Not only will routinely replacing your filter improve your home’s odor, but it may also help any allergy sufferers in your family breathe easier. When you don’t have a decent line of defense – your filter – to keep dirt and dust held back, allergens float freely through the air in your home.


3. There’s a problem with your home’s ventilation.


Your home needs to be properly ventilated so that fresh air can be drawn in and circulated throughout your living space. When there’s adequate ventilation in your home, you are less likely to have problems with excess moisture in the air (humidity) and foul odors.


Here are some common warning signs of ventilation problems:

  • Your home smells musty, similar to a “dirty sock” odor.
  • Condensation can be seen forming on glass surfaces, such as your windows.
  • Rust is seen forming on pipes or metal surfaces.
  • Mold is seen growing on walls, floors, countertops, and other surfaces. 


Ventilation problems won’t just lead to a smelly home, they can also cause serious health issues for your loved ones. Inadequate ventilation can lead to dangerous mold growth, which could cause respiratory problems, headaches, cold/flu-like symptoms, skin or eye irritation, and a variety of other medical issues.


If you suspect that this is the problem in your home, be sure all exterior vents are free from obstructions. Check your attic and roof vents, as well. These often are forgotten, and if they close or get blocked by outdoor debris, it may decrease fresh air flow into your home, thus leading to foul odors and potential health problems.


4. The evaporator coils are creating a smoky/burning odor.


If you have smokers in your family, the cigarette smoke could get pulled into your cooling system and pushed through all the vents in your home. Regardless of where you smoke in the home – even if you limit it to just one room – the tobacco fumes will get drawn in and circulated. Tell all tobacco users to smoke outside. To get rid of the smoke odors already on the coils, contact a cooling expert to sanitize the unit.


If you don’t have any smokers in your home, the problem could signify an issue with the electric igniter. If that’s the case, you will need to shut the unit off and contact a cooling professional as soon as possible.


5. There’s an electrical problem.


If your heating or cooling system is creating an “electrical” smell, it may be a result of several different issues, including overheating, a clogged filter, or a problem with the motor. First, shut off the system. Next, check the air filter’s condition. If it’s dirty and dusty, replace it. Turn the unit back on and see if you still smell the same electrical odor. If so, shut the unit off and contact a heating and cooling professional. Attempting to fix issues with the motor or wiring with an HVAC unit could be dangerous if you don’t know what you are doing, so don’t try to repair it yourself!


Prevent foul-smelling odors in your home.


Be sure to schedule routine heating and cooling maintenance for your systems. During your maintenance appointment, an expert will thoroughly clean and inspect all working components of your systems to be sure everything is in working order.