Furnace Noises and What They Mean: Tips for Homeowners

Furnace Noises and What They Mean: Tips for HomeownersDuring the winter when you turn on your furnace, you are going to start hearing noises coming from it. That’s normal, and shouldn’t send you into a panic! There are some more unfamiliar noises though, that could mean trouble. For homeowners, it’s nice to be familiar with furnace noises and what they mean. 

I’ve been working with furnaces for 20+ years now, and in the Chicago, Illinois area where we live, I know how important your heating system is. Through years of experience and hearing a furnace make almost every noise it can produce, I’ve come up with this article going over different furnace noises, and what they mean for your heating system. 

If you are having problems with your furnace, give us a call right away at (630) 504-8688, or contact us online. We can help you if your furnace isn’t getting the job done. 

What Are Normal Furnace Noises?

As a homeowner, it’s nice to understand the difference between normal and abnormal furnace noises. Normal furnace noises are usually a quiet humming or a soft whirring sound. Just like any machine, some noises are going to come out of it, and if it’s these, it means everything is just fine. These sounds are produced by the blower motor or the air moving through the ductwork. You may hear your furnace kicking on and off. This is also a normal noise. Here are some of the other noises you may hear coming from your furnace. 

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14 Common Furnace Noises and What They Mean


A furnace that makes a banging noise, especially when turning on, could indicate a delayed ignition. This is often caused by a buildup of gas or oil, which then ignites suddenly, creating a loud bang. You don’t want to let this happen for too long. Call a professional and have it looked at. If the gas isn’t igniting properly, it could cause damage, and also become a dangerous situation. 


A grinding noise typically suggests a problem with the furnace’s blower motor. Bearings within the motor may be worn out, causing friction and grinding sounds. This is one that may start small, and gradually become a bigger problem. Call a professional right away to get this problem fixed, or it could lead to a more expensive repair. 


Clicking sounds can be normal during the start-up and shut-down cycle. However, persistent clicking may point to a faulty relay or problems in the electrical system. If you hear repeated clicking in a short period of time, call in a professional. If you only hear clicking when the system is turning off and on, you should be just fine! 


Is screeching ever a good noise? Screeching sounds often come from a malfunctioning blower motor or a loose belt. The belt may have come loose and need an adjustment, or it could need a replacement all together. Ignoring this noise can lead to a complete breakdown of the blower motor. 


Squealing is another sound that almost always means nothing good. Squealing sounds are similar to screeching but usually indicate a different problem. This noise often means there’s an issue with the furnace’s fan belt. A professional should be able to fix this up no problem. 


A furnace making popping noises, particularly when turning on, can signify the expansion and contraction of ductwork. This is no big deal, and shouldn’t be something that needs fixing. If you hear popping over and over and over, it could mean the ductwork needs adjustments. 


If Your Air Filter Is Clogged, It Could Be Causing Problems

A booming sound is similar to banging and is often a sign of delayed ignition. This can be due to a dirty burner, lack of airflow, or other issues causing an accumulation of gas or oil. We recommend service at the start of heating season to clean all these components, and make sure the system turns on with no booming, banging, or clanking! 


Chirping is typically a sign of a minor issue, such as a slightly misaligned or dirty fan belt. No, there is not a bird in your furnace. Regular furnace maintenance can easily make sure you keep the chirps, and birds, out of your heating system. 


Whining noises can indicate a strain on the furnace’s motor. It could be due to a clogged filter or an issue with the motor bearings. You can change your filter on your own, but if the system keeps whining, you should call in a professional. They will be able to assess the problem, and cheer your furnace right up! 


A scraping sound, like metal on metal, often points to a serious problem with the blower wheel. If the wheel is loose or broken, it can scrape against the casing, requiring immediate repair. We recommend turning your furnace off if there is severe scraping, as to prevent it from causing any further damage inside. 


A rumbling sound from a furnace, particularly when it’s shutting down, could indicate incomplete combustion. This might be due to a dirty or malfunctioning burner. Another problem routine service takes care of. 


Buzzing noises can indicate electrical issues, such as loose wiring, a failing capacitor, or problems with the electrical relay. Electrical issues should always be addressed by professionals. 


A whistling sound often means there is a problem with the furnace’s airflow. It could be due to a clogged filter, leaks in the ductwork, or an improperly sized duct system. This is not the end of the world, but can be frustrating. It can also be an easy fix, that you may be able to take care of yourself if it’s the ductwork. A professional should also be able to do the trick. 


Knocking sounds in a furnace can be due to several issues, such as loose internal components or problems with the ductwork. This is one you should let the pros handle. Taking apart a furnace to find the issue inside can be dangerous, and harmful to your heating system.

If you are hearing any crazy, and unusual noises coming from your furnace, we can help! We specialize in furnace repair in Elgin, IL, and the surrounding areas. Give us a call at (630) 504-8688, or contact us online to have a look at your furnace!


Should you be able to hear your furnace?

As we’ve mentioned, there are normal furnace noises, and noises that should give you cause for concern. Regular furnace maintenance can help keep your heating system running quietly and efficiently.

Why is my heater making a weird sound?

Weird sounds from your heater, such as grinding, popping, or screeching, are indicators of potential issues. It could be something small that needs adjusting, or a sign that you have a bigger problem. 

Why does my furnace sound like a freight train?

If your furnace sounds like a freight train, it could be due to a serious issue like a blocked exhaust vent or a problem with the burner. Turn your furnace off and call in a professional right away!