(602) 842-0009

All Articles

4 Weird Smells You Might Get When You Turn On Your Heat

“My heat smells funny, should I be worried?”

November is here and—like clockwork—so are the daily calls from homeowners who have turned on their heat for the first time and noticed some odd smells.

To help determine what’s normal and what’s not, we’ll take a look at 4 common just-turned-on-the-heat smells and explain what they mean.

Scent #1: Dusty or burning smell

Is it normal?


What does it mean?

If you smell a dusty or burning smell the first few times you turn on your heat, it’s most likely dust and dirt that’s settled on components inside your heating system throughout the summer.

As you fire up the heat, those dust particles burn away, producing a weird burnt/dusty smell.

What to do:

Just wait it out, the smell should go away naturally as all the dust slowly burns off. If the smell lingers after a few days of running your heat, though, have a professional inspect your system—it may need cleaning.

Scent #2: Dirty socks or mildew smell

Is it normal?

Well, it’s not dangerous but it’s definitely not ideal.

What does it mean?

If you have a heat pump and your home suddenly smells like a locker room after you turn on your heat, you most likely have a buildup of bacteria on your indoor coils.

But if you have a furnace, don’t worry. This problem doesn’t typically happen with furnaces because the internal components of a furnace usually reach temperatures high enough to kill off any bacteria.

Heat pumps, on the other hand, can’t produce temperatures as high as this. You see, heat pumps don’t produce heat like furnaces do; instead they transfer heat from the outdoor air and move it inside your home. And because the outdoor temperatures are relatively low in the winter, heat pump coil temperatures usually only reach around 105° to 130°—the perfect temperatures for microorganism activity.

What to do:

Have a professional inspect and clean your coils.

Scent #3: Rotten eggs or sulfur

Is it normal?

Absolutely not.

What does it mean?

A rotten egg or sulfur smell typically only comes from gas furnaces and indicates a gas leak that could cause a fire or explosion.

Gas furnaces are fed natural gas via enclosed gas lines. When the gas ignites safely inside the furnace, it creates heat that warms the air inside your home. But, sometimes, leaks in the gas line or the furnace itself allows gas to seep into your home. And then, all it takes is a small spark to set off a deadly explosion inside your home.

What to do:

Evacuate your home and call a professional immediately.

Scent #4: A burning electrical smell

Is it normal?


What does it mean?

Well, this smell could mean a lot of dangerous things such as frayed wires or failing motors.

Depending on what’s actually causing the smell, you could quickly end up with an electrical fire or a dead motor (i.e. an expensive repair).

What to do:

Have a professional inspect the system to find and fix the source of the smell.

Want to avoid these smells altogether?

The best way to avoid weird smells (or expensive repairs) this winter? Maintenance.

During a maintenance visit, our techs will inspect your heating system for any problems such as gas leaks, frayed wires or failing motors. Cleaning dusty/dirty components is an extra charge but may be what your system needs to run efficiently for the season ahead.

Just schedule your furnace maintenance with us and we’ll send out a tech right away.