Warning! These 4 Common HVAC Odors Need Prompt Action

When you smell something strange inside your home, the first thing you may think of is the trash in the kitchen. But before you blame someone who forgot to take it out, make sure to be aware of what kind of smell that is. You might not know it, but it may be coming from something serious and need urgent attention. 

As you try to trace where the smell is coming from, do not disregard the fact that it could be from your HVAC system. Especially if it’s a burning smell, this could be really alarming. So, we’ve compiled three of the most common HVAC odors and what they mean, so you can be alert and do something about it.

1) Burning

This is one of the most frightening smells that you can experience at home. This can occur when you run your HVAC system and then notice that a burning smell is coming from it. Commonly, this is caused by the accumulated dust over a period of time and is burning off the system. The smell is like there are burning electrical wires and materials. 

What To Do:

To make sure it won’t get serious, you may need to run the HVAC system for 20 minutes. Wait if the smell will disappear. If the smell persists, make sure to contact a licensed HVAC professional.

2) Mold or Mildew

Have you ever noticed that there’s a smell like a soiled sock or gym locker in your home? It could be caused by mildew or mold. In fact, many house owners are complaining about such a smell from their HVAC system. Of course, who wouldn’t want to be disturbed by such irritating smelling while they are sleeping or watching TV? This type of smell usually occurs when your HVAC system’s mode is switched from heat to cool. When the system has not been used for a long period, bacteria and mold can thrive on the drain pan and evaporator coil.

What To Do:

Make sure to check and clean your filters. A filter that is free from dust and dirt will prevent or reduce the mold or mildew smell. This is also a critical preventive measure to maintain the proper functioning of drain pans and coils. In some cases, an HVAC expert will advise you to use a special kind of spray to clean the coils. They can also be fixed or replaced using an epoxy-coated coil.

3) Rotten Egg

Here’s one of the nightmares of homeowners. The smell of a rotten egg is considered one of the most dangerous when it comes to HVAC odors. Why? It signals that there could be a gas leak. So, in the instance that you notice a smell of rotten egg or sulfur in your home, make sure to turn off the HVAC system immediately. Windows should be opened, and avoid operating any electrical appliances or tools inside your home. Natural gas is actually odorless, but to have a warning signal during a leak, utility companies add certain chemicals to make its smell distinctive. The smell could mean that there is a gas leak from the furnace, gas valves, or gas pipes.

What To Do:

Immediate actions include turning off the system, opening the windows, and leaving the house. Call an HVAC professional or a gas company in your area.

4) Urine or Trash

This type of smell usually comes from the vents and maybe a signal that critters are thriving in the HVAC equipment or duct system. Or, there can be mice, possums, or cats making the system their home. If that’s the case, expect to smell urine and waste materials from that.

What To Do:

Make sure to inspect your HVAC equipment and duct system to see if there are animals on it. However, do not try removing them from the area because you might get electrocuted. You may also get harmed by these animals. It is recommended to call a service technician or a pest company to clean the area from infestation.


Do not take for granted the smells that you may notice coming from your HVAC system. You must be aware of what each smell means so that you can fix them properly. You will also ensure the safety of your family and property if you’re familiar if the smell is fatal and may need immediate action. Always consider asking for the assistance of a reliable HVAC company.

For all your heating or air conditioning repairs in Summit, NJ, make sure to call us at A1 LLC. Our reliable team is composed of experienced technicians who are dedicated to promoting quality services. Book a service today!

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