HVAC Odors That Every Home & Business Owner Should Know

smoke in the air

HVAC Odors you should know about

There is a popular saying in Texas that states, “If you don’t like the weather in Texas, just wait ten minutes, and it will change.” When it comes to temperature fluctuations, many Texans know that within one day, the heater may be on in the morning and the air conditioner could running in the afternoon. That’s why it is very important to know what smells coming from your HVAC systems mean, and what should be done next.

Rotten Eggs

An odor that resembles sulfur or rotten eggs is not one to take lightly. This smell could indicate a natural gas leak. Although natural gas does not have an odor itself, gas companies add a sulfur smell to warn residents in case of a leak. Even if you are not sure this is what is happening, make sure to open windows to ventilate the house, and leave your residence. Call the gas company when you are in a safe area.

Burning Dust

One very common odor that comes from your heater is a burning or dusty smell. Although this smell may be a nuisance, it is not one to worry about. Dust from not using the heater is burning off once the heater is turned on for the first time in cold weather.


If a chemical or formaldehyde scent fills your house, it most likely means there is a crack in the heat exchanger component of the furnace. This issue needs to be checked out by an HVAC professional to make sure you are not at risk for fires or carbon monoxide fumes.

Metallic Or Electrical Burning

If a strong metallic or electrical burning smell is present, this may indicate your furnace actually getting too hot and literally burning components of the furnace itself. As mentioned above, a professional is the one to call to check out this serious issue.


Although this smell may not put you in immediate danger, a musty smell can indicate unclean air. There are many different causes for growth in your system. Controlling mold is vital not only for your health, but for the health of your HVAC system. Contact an HVAC technician to look into this issue and to help with tips on how to prevent this from happening again.


Although smelling smoke in your residence is alarming enough, seeing the smoke is an even bigger issue. Shut off your furnace immediately and contact a professional. This can be caused by burning wires in the blower cabinet.


Smelling oil can be caused by two different things. First, it could mean an oil leak. If oil is seen, this could mean a tightening is needed for either the filter, tank, or oil line. If oil is not seen, make sure to look for smoke or listen for any strange sounds. This could indicate a problem with the oil burner. Call an HVAC technician to have either of these issues addressed.

Overall, if any odor you are not familiar with is coming from your furnace, cut your heater off and contact an HVAC professional. Even if the issue is not severe, it may mean saving your life from fire or carbon monoxide fumes.

Help From The San Marcos TX Air Conditioning Repair Experts

Noticing an unfamiliar odor coming from your heater or air conditioner? Contact AirOne Heating and Air Conditioning today to speak to a San Marcos air conditioning expert who can help.