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Furnace Making Popping Noise? Top 3 Causes (+ Fixes)

Just as you’re getting ready to dose off at night, you suddenly hear a popping noise coming from the furnace. A furnace making popping noise is an annoying and common problem that can keep you up at night. You need to check several things when you hear a popping sound coming from the furnace, ducts, or vents.

If your furnace is making a popping noise, it’s because you have poor ductwork insulation, a dirty or faulty air filter, or the vents aren’t large enough. To fix the problem, you have to insulate the ductwork, inspect and change the air filter, and ensure you have vents that are large enough.

This article will help you get to the bottom of your furnace popping noise. I’ll also give you step-by-step instructions on how to fix each problem. Let’s get started!

Poor Ductwork Insulation

Ductwork forms a critical part of your furnace and the complete HVAC system in your home. It consists of lines and vents. Air is pushed through the ductwork from the furnace and then escapes into the rooms throughout your home. 

When ductwork is installed, insulation needs to be applied to the entire line. The insulation ensures air doesn’t escape at any point except through the vents, allowing air to circulate in your home. 

When there are problems with the ductwork insulation, that can lead to your furnace making a popping noise. Poor insulation can also lead to insufficient heating and higher electricity bills. 

How To Fix

You first need to confirm that there’s a problem with the ductwork insulation. 

To do this, walk along the lines and check if there’s air escaping at any point. 

Of course, a popping sound in a specific part of the line is a dead giveaway that air is escaping from that spot. This allows you to get directly to the source and pinpoint where the sound is coming from,

If you find the problem area, check what’s wrong with the insulation. You might have to reinstall the insulation. Sometimes, you may be able to fix the current insulation without having to redo anything. For example, if the insulation has come loose, you could use duct tape to get it back into place.

Here’s a video explaining how to insulate ductwork:

The Air Filter Is Dirty or Damaged

The air filter reduces the number of particles flowing through your home. This part of the furnace also enhances the overall air quality in the building, a great way to reduce allergies. 

The air filter gets dirty over time as you use the furnace. There might even be a thick layer of debris on the filter. If that’s what your furnace filter looks like, the air can’t effectively push through the filter. And even though the air isn’t going through the filter, the blower will continue to push the air toward that area.

While a dirty air filter is often associated with a whistling sound, it can also turn into a popping noise. This happens when too much air builds up behind the air filter. In addition to producing an unpleasant sound, excessive air build-up can cause severe damage to the furnace and ductwork. 

How To Fix

Air filters need to be cleaned frequently, regardless of any popping and whistling sounds coming from the furnace. You should inspect and replace the air filter regularly. It’ll save you from large expenses on other parts of the HVAC system down the road.

Here’s what you need to:

  1. Locate the furnace panel that holds the air filter. 
  2. Remove the panel using the appropriate tools.
  3. Remove the air filter. 
  4. Run some water over the filter to remove the accumulated debris. If it’s not a reusable filter or it’s in rough shape, replace it with a new one.
  5. Dry the filter before putting it back into the furnace. If necessary, use paper towels to dry the filter, but never put a moist filter into your furnace because you risk damaging the furnace.

If the filter is damaged, it’ll cause particles to escape into your home and will likely continue making popping sounds, even after cleaning. 

If you need to replace the air filter in your furnace, take a look at the following video: 

The Vents Aren’t Large Enough

If you installed the furnace recently, you should check the size of the vents and ductwork in relation to the furnace. Popping sounds are a common problem when a system is newly installed. It can also be an issue when using existing ductwork with a new furnace. 

When the vents and ductwork aren’t big enough to handle the rate at which air is blown through, you’ll hear all sorts of noises. Just like with poor ductwork insulation, air build-up can cause popping noise.

How To Fix

If the air vents and the ductwork are too small for the furnace, consider one of three options:

  • Have the ductwork replaced and install bigger vents. This process can take some time. Bigger ducts need to be installed to ensure there’s enough space for air to flow through. 
  • Get a different furnace. If the furnace is new, you might be able to get a free replacement. Contact the company you bought it from and explain the situation to them. In many cases, the company will agree to exchange it for a different model. If the alternative model you choose has a higher price tag, you simply pay the difference. 
  • Reduce the furnace’s power. Most furnaces allow you to set the specific power at which air is blown through the vents. Set this to a lower number.

While the most cost-effective solution here would be the last one, it does mean you’ll get less hot air throughout your home. In other words, heating may be less efficient compared to having the ductwork or furnace replaced. 

Since lowering the power output of your furnace is free, that’s a no-brainer you should try first. You can also contact an HVAC expert to see what solution works best for you.

Summary

A furnace making a popping noise may signify something small that can be fixed without much effort. There are also more serious problems that can cause an annoying popping sound coming from the furnace.

A professional can diagnose the problem and ensure appropriate fixes are implemented. Have a professional inspect the furnace when you can’t fix it yourself or need to get inside the furnace to fix the problem.

Author

  • Jake Alexander

    Jake is a freelance writer from Pennsylvania who enjoys writing about science and sports. When he's not writing for Temperature Master, he can be found watching the NFL or playing basketball with his friends.

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