What Is Making My Furnace Smell?

How to Determine the Cause of Furnace Odors

stinky furnace wisconsin By now, you’ve probably started up your furnace to chase away some of the early fall chill from your Wisconsin home. If you’ve already taken care of getting your heating oil furnace checked and serviced for the winter ahead, it will more than likely perform without a hitch this season.

But often, when regular heating maintenance has been put off, your furnace will give you warning signs of a coming problem – and those signs will often come in the form of odd smells.

Strange odors emanating from your furnace can indicate several problems. Some are easy to fix, others are more complex. Here are five common furnace odors you may encounter and what they may mean for your heating equipment.

5 Common Furnace Odors

  1. Heating oil odors. If your heating oil furnace is working properly, you should never smell fuel oil. An oil smell could be caused by a leak, burner troubles, a heat exchanger failure or exhaust system problems. You should reach out to your equipment service provider as soon as possible to correct this situation.
  2. Smoky odors when your furnace operates. If a fireplace or exhaust fan is running at the same time as your oil burner, this can result in a smoky odor because a backdraft is pulling flue gases through the exhaust system and into your home. Please keep this in mind if you detect a smoky odor.
  3. Dusty/burning smell. A dusty, burning smell coming from your heating oil furnace can be quite common, especially early in the heating season. The smell is often the result of your furnace burning away dust and dirt that has accumulated during the offseason. If dust is the cause, the burning smell should go away after a few hours. If it doesn’t, try replacing the air filter in the furnace–which you should do at the beginning of the season anyway–before you request service from a heating oil service professional.
  4. Electrical /burning wire smells. Electrical smells coming from your furnace are typically a sign of overheating. If your furnace is cycling often (turning on and off) for no apparent reason, it may be your equipment protecting itself from a more substantial (and costly) breakdown. Give your furnace a rest for a few hours; if the problem begins again when you turn it on again, arrange for service.
  5. Mechanical smells. Worn out rubber and grinding metal parts will produce an odor that resembles electrical overheating. These smells can indicate a serious problem that needs immediate attention. Shut your heating system down and call for service.

The Air Filter on Your Heating Oil Furnace

If you had a heating tune-up done recently for your heating oil furnace, your technician started you off with a fresh, clean air filter. Moving ahead into the heating season, one way to help your furnace operate without any trouble is to change or clean your furnace’s air filter as often as the manufacturer recommends. In general, you should check the filter’s condition about once a month and change/clean it when necessary.

If your air filter gets clogged with dust and other debris, there is less room for air to flow through your system and through your home. Your furnace will need to work harder to circulate air, which will result in higher heating bills. Your home will also feel less comfortable and the indoor air quality will degrade. If neglected for too long, a dirty air filter can even result in your furnace shutting down.

If you think your heating oil furnace has seen better days and needs to be replaced, see what you can expect with a new furnace installation.