What Your Furnace’s Noises Mean

Even when a furnace works correctly, it can still make a surprising amount of noise--especially if it's hard at work keeping you warm during an Illinois winter! Over time, most people get so accustomed to their furnace's "white noise" that they end up tuning out most of it. However, some furnace sounds could indicate an issue with your heating equipment, so it's critical to understand which noises are normal and which ones mean trouble.

What Does a Normal Furnace Sound Like?

A typical furnace may make chirps, rattles, hums, pings, or crackles. A hum happens typically when the furnace burner lights, and you will hear a click after the hum. Rattles often occur when the furnace is cooling down. If you hear a ping, it may be due to air ducts expanding and contracting. Meanwhile, crackles happen when the furnace's metal parts turn off as it shuts down.

Which Furnace Sounds Are a Cause for Concern?

According to ENERGY STAR, the average household spends $2,000 a year on energy bills. A large portion of this goes toward heating and cooling costs. If your furnace is not functioning correctly, it could be using up more energy and causing even higher energy bills than usual, so be sure to keep an “ear out” for unusual noises that may indicate an issue.

Some of the following noises could be a sign of a major furnace problem.

  • Screeching: This noise often develops because of a problem with your fan belt, motor, or a bearing.

  • Scratching/Scraping: This frequently means that there’s a problem with the blower wheel.

  • Booming: A minor booming noise can occur when your ductwork expands and contracts. However, if a loud pop or bang occurs when your furnace turns on, it may be a sign that the equipment has dirty burners or a combustion issue.

  • Clunking: Any bumping or clunking sound could be an indication that the fan belt has cracked or that the fan blade has become misaligned.

Any time your furnace makes an abnormal sound, you should consult with an HVAC technician to inspect the unit. In some cases, your furnace might only need some routine maintenance, but it’s best not to postpone a service call. After all, you don’t want to wind up with an expensive repair that could have been prevented.

You might also like:

Preparing Your Furnace for Cold Weather

What to Do If Your Furnace Is Blowing out Cold Air

To schedule furnace repair and maintenance in Belleville, be sure to contact Morrison Plumbing, Heating and Air at (618) 352-5599.