Why Does Your Heated Air Smell Like Chemicals?

If the air coming out of your vents smells a little dusty now and then, it's not a big deal. You probably just need to change the air filter or have your ducts cleaned. But when the air takes on a chemical odor that reminds you of preservatives, that's a whole other story. A chemical smell coming from your furnace usually indicates that the heat exchanger has become damaged — and that's a problem that can have deadly consequences. Read on to learn more.

What is the heat exchanger?

Your furnace works by burning fuel. The fire makes a component called the heat exchanger hot. Air passing past the heat exchanger becomes warm and is then blown into your home. When everything is working properly, your heat exchanger is sealed with no cracks or gaps in it. It encases the flame.

Why do heat exchangers crack?

This problem is most often seen in older furnaces. The heat exchanger can crack if the heater is put under excessive stress by a clogged air filter, or if the burner is always dirty. Sometimes, it may crack due to a manufacturing flaw.

Why is a cracked heat exchanger dangerous?

When a crack develops in the exchanger, that means that gases generated by the flame can travel through the crack and into the air that gets passed through your home. One of the gases generated when fuel combusts is carbon monoxide. CO is a poisonous gas. It can cause headaches, fatigue, and confusion. In some cases, it kills people before they notice symptoms or before they narrow down the cause of their symptoms and realize they don't just have the flu.

What should you do if you suspect your heat exchanger has cracked?

You don't have to turn the furnace off immediately. There are many cases where a cracked heat exchanger does not release CO, and yours might be one of them. Make sure you have a working CO detector near the furnace. If it goes off, leave the home immediately.

Otherwise, just make an appointment with your HVAC contractor and have them look over your furnace ASAP. They may recommend replacing the heat exchanger, but since this can be a costly repair, you might want to just invest in a new furnace.

Don't ignore those chemical smells coming from your furnace. They could mean trouble for you and your family, and the only way to be sure is to hire the best heating and air conditioning contractor to have a look.