Furnace Making Banging Noise When It Shuts Off
Troubleshooting Loud Sounds from your Heater


During cold Colorado winters, your furnace is probably the hardest working thing in your home. You probably hear it kick on and off periodically to keep up with making your home reach and maintain your desired temperature. But while those soft hums of a working furnace may be easy to ignore, some sounds are not.
Do you hear odd noises from your furnace? Is your furnace making a banging noise when it shuts off? You may be wondering if these sounds are something you should worry about. Depending on what you hear and where the sound is coming from, odd noises could indicate various problems with your heating system.
At DALCO Heating & Air Conditioning, we’ve encountered all sorts of furnace problems and sounds. We break down some common noises heaters can make and what potential issues each could mean.
Troubleshooting 4 Types of LOUD Furnace Noises
Heater Shuts Off with a Banging Sound!
You may also hear this noise when it turns on. If you hear booming or banging, you might have a serious problem. A loud bang comes from your furnace when it first turns on could indicate a gas build-up. However, a furnace making a loud bang could also mean an issue that isn’t severe.
If you hear a banging from your ductwork, that could be the loud sound of your ducts expanding or contracting. But if you’re not sure whether this sound came from the ducts, don’t take any chances.
What should you do?
Turn off your heater and call for a fix. This is potentially a dangerous problem that requires professional help. Call us at (785) 776-5012, and we will inspect your heating system. If you have gas building up inside your furnace, this could cause serious problems like a cracked heat exchanger.
How to keep this problem from happening?
The good news is that a gas build-up is a preventable problem. Dirty burners can cause it, so maintenance on your heating system may stop it from occurring. Call DALCO for professional maintenance repair service to ensure your system is working safely and efficiently.
Furnace Making A Rattling Sound
Are you hearing a persistent rattling coming from your HVAC system? It could indicate a few things, including something as minor as a loose screw or panel that needs to be secured.
However, other issues can cause a rattling sound. Have you heard a loud bang before the rattling? That combination of sounds could happen when a heat exchanger has become damaged, which puts your home at risk for a carbon monoxide leak.
What should you do?
If you feel confident in your repair skills, you could examine your furnace for any loose screws or panels and tighten them as needed. However, the problem may be hard for a homeowner to diagnose on their own. Contact DALCO for a professional furnace repair anywhere in the Denver metro area.
Sound of Grinding Metal
If you hear a noise that sounds like metal on metal or clanking, that is something you shouldn’t ignore. Those metal sounds could mean you have a serious problem. It’s possible that your blower fan has gotten out of place and is banging up against the blower house casing.
What should you do?
Turn off your furnace and get it fixed before using it again. There may be problems inside the blower. These could be minor issues requiring little repair or something more problematic like a broken blower fan that needs to be replaced.
A Squealing Sound
While this may be quite an annoying sound to endure, the good news is that it could indicate some pretty minor issues. But it’s still not something you should ignore. Your heater may have a faulty belt, or there could be a problem with your fan motor. Some components in your system may simply need to be lubricated. Regular maintenance could help prevent this problem from happening.
What should you do?
Contact us. While this sound could indicate relatively minor issues, you want a trained HVAC technician to diagnose and fix accurately. Most likely, you need repairs that our furnace repair technicians can handle quickly and easily. But even minor issues, when left ignored, can turn into significant, expensive issues.
Normal Furnace Sounds
Your system will make sounds occasionally, and many of them don’t indicate a problem. You may hear chirping, humming, or even a pinging. These sounds are usually harmless and normal for a furnace.
But if you’re ever in doubt, give DALCO a call at 303-979-7541. Our experienced technicians can repair any type of furnace or heating system. It’s always best to check out potential problems that may be fixed quickly and cheaply before becoming big and expensive.
