Noisy Furnace – What is Causing Weird Furnace Sounds?

Emergency Furnace Repair

In this post, we review the causes of furnace noises and offer troubleshooting tips and solutions to what could be causing the problems.

A noisy furnace can be annoying for sure.

Even worse though, furnace noise could be the sign of a more serious issue that needs to be checked.

For furnace repairs in Warrenville, Naperville and western suburbs, call us today:630-393-9500

Let’s review some of the different types of furnace noises, what they could be caused by and what to do next.


Common Furnace Noises

  • Scraping or Grinding
  • Thumping or Banging
  • Humming
  • Screeching or Squealing
  • Rumbling
  • Pops or Bangs

If you are trying to troubleshoot the furnace noise issue on your own or ready to call a furnace repair technician, make sure that you can identify the type of noise the furnace is making. This can help you or the repair person narrow the list of possible issues and find a solution quicker.

Related: American Standard Furnace Troubleshooting Guide


Furnace Noise Causes

American Standard FurnacesScraping or Grinding Sounds

Scraping sounds, grinding noises or other types of metal on metal sounds are usually caused by three main problems: a loose blower wheel, a broken blower wheel or a broken motor mount.

A loose blower wheel can shake, rattle, and rub against blower housing. If this is fixed quickly, it can prevent more serious damage to the wheel and its housing. A broken blower wheel will vibrate in its housing, which can result in squealing, scratching, banging and metal on metal sounds. A broken motor mount will cause the blower wheel rattle against the housing.

These issues can often be diagnosed by homeowners but we don’t recommend trying to DIY repairs to one of the most important pieces of equipment in your home.


Thumping or Banging Sounds

Thumping, banging, and vibrating sounds are usually caused by an unbalanced blower wheel. Sometimes the actual motor can also become unbalanced. This can be a serious issue which can lead to more serious damages to your furnace. It’s time to call a professional.

Related: Reason furnace turns on and off frequently


Humming Sound

A humming sound in the furnace could be caused by a few different things. If you hear humming but your furnace is functioning normally, you likely have a loud transformer. Furnace problems and humming can be caused by a bad interior fan or capacitor. A third possibility is once again the blower fan. It possible the motor needs to be lubricated, but it could also be that the blower motor is beginning to fail and needs to be replaced.


Screeching or Squeeling

Screeching sounds could be caused by a loose fan belt or also a lack of lubrication. Applying oil or tightening your blower belt should stop the screeching or squealing sound.


Rumbling Sound

A low rumbling can mean there is a problem with your burner. It could just be a build up of dirt and grime. In some cases it can also be caused by a heat exchanger leak, which can be a serious issue and even dangerous, so call an HVAC company right away.


Furnace VentPopping or Banging Sounds

Popping or banging sounds from your furnace could be caused by dirty burners. The dirt buildup can delay the ignition, causing a gas build up that leads to a loud bang or pop when the furnace turns on. Another possible cause is that the start-stop cycle of your furnace is causing the sheet metal siding to bend inward, causing in a banging or popping sound. This could be caused by undersized air ducts, closed vents or even a clogged filter.


We hope that this list can help you identify potential problems. In some cases, furnace noises can indicate a serious problem, so please call a professional HVAC repair person.


A Climate Services & Systems Inc.Do you need help getting your furnace working?

Contact us online or phone 630-393-9500

We serve Warrenville, Carol Stream, Downers Grove, Geneva, Lombard, West Chicago, Naperville, and Batavia and nearby communities.

2019-02-25T13:49:44-06:00Furnace and Heating|