How To Watch, Listen, And Smell For Furnace Problems

You're relying on your trusty furnace to keep your family comfortable through those chilly times of the year. But how can you tell when your furnace is becoming less than trusty? The earlier you can detect a furnace problem in the making, the better — not just for comfort reasons but also to safeguard your loved ones against hazardous developments. Fortunately, your own senses can tell you much of what you need to know in time to put out a call to your local furnace repair expert. Take a look at how you can use your sense of sight, hearing, and smell to troubleshoot a troublesome furnace issue.

Hiding in Plain Sight

Some furnace problems can send out such seemingly innocent signals as an unusual amount of dust in your household air. If you find yourself coughing, sneezing, wheezing, or rubbing your eyes more frequently than you once did, your furnace may not longer be filtering and cleaning the air. You might have a filter that needs cleaning or replacing, or you might need to have a leak in your duct system patched up. Unusual amounts of condensation on your walls or windows could signify a different, potentially more dangerous problem: high carbon monoxide levels in your home. That's because a furnace produces both water and carbon monoxide when it burns fuel. If water is entering your household air (instead of being eliminated as exhaust) due to a furnace malfunction, there's a chance that carbon monoxide may be doing the same thing.

Your eyes can provide you with yet another clue that your furnace is in trouble. Take a look at your furnace's pilot light flame. The color of the flame should be blue, with only tinges of yellow; if it's solid yellow, the furnace isn't burning fuel efficiently (and possibly releasing excess carbon monoxide as a result). A cracked heat exchanger is one possible culprit in these situations.

The Sounds of Trouble

Your ears can alert you to some furnace problems that might not be apparent to your eyes. For instance, are you hearing strange scraping or thumping noises when your furnace operates? Both of these sounds can be caused by blower wheel and/or blower motor damage. Banging noises may be the result of negative air pressure causing the sheet metal sides of the fan to flex inward. These changes in pressure could mean that you need to clean a blocked air filter. Humming sounds can indicate electrical issues, while a pervasive rumble can alert you to a bad burner that requires immediate professional attention.

Following Your Nose

What's that smell? Sometimes your nose can turn your attention to furnace problems — and if that smell isn't a pleasant one, the news probably isn't good either. The classic example is a "rotten egg smell" in the air. This sulfurous odor usually means that something is wrong with your heat exchanger, placing you at risk for carbon monoxide exposure. A burning-plastic smell can alert you to a short circuit occurring within your furnace's electrical wiring, or it could mean that your fan motor is on its last legs.

Not all furnace smells signal imminent danger, but that doesn't mean that they should be ignored. For instance, a musty or dusty smell might not send you into a panic, but it could serve notice that you need to replace your air filter or get your ducts cleaned — especially if anyone in your household has an allergy or sensitivity to airborne particles. (Dust can also cause an unpleasant "burnt" smell when you first activate your furnace after a season of inactivity, but this nastiness should disappear quickly.)

If your furnace is having problems, contact a furnace repair technician in your area for help.