Skip to Content

Gas Fireplace Making Noise When Off? Here’s Why (+ How To Fix)

It’s natural for gas fireplaces to make noise as it’s burning fire. However, if you still hear noises when it’s turned off, it’s a sign that something is wrong and needs your attention. Some of these noises are benign and nothing to worry about, while others pose a fire hazard and demand prompt action.

Your gas fireplace is making noise when off because of contracting metal frames, dirty fan blower, the wind blowing down the chimney, insect infestation, gas leakage, gas supply line blockage, or problems with the pilot light. To stop the noise, diagnose what’s causing it and fix it accordingly.

In this article, I’ve put together an in-depth look at different reasons behind your gas fireplace making noises while turned off. I’ve also discussed the different types of noises you can hear from a fireplace, what causes it, and potential fixes. 

Reasons Your Gas Fireplace Is Making Noises When Off

Here are 7 reasons your gas fireplace is making noises when off:

  • Contracting metal frames.
  • Dirty fan blower.
  • Wind blowing down the chimney.
  • Insect infestation.
  • Gas leakage.
  • The pilot light is burning with a low flame.
  • Gas supply line blockage.

In the following sections, I’ll look at the potential reasons your gas fireplace might be making noises even though it’s turned off. Also, along with each cause, I’ve mentioned possible fixes to help you stop the noises.

The Metal Frames Are Contracting

Does your gas fireplace make a metallic snapping, clicking, or clunking noise when the fireplace is off? 

Do you hear this noise only after turning off the fireplace? 

And lastly, do you have a metal frame inside your gas fireplace for holding imitation logs in place?

If you answered yes to all three questions, the sound is likely coming from the metal frame as it cools down and contracts in size.

When the gas fireplace is running, it generates heat, which causes the metal frame to slightly expand in size. However, after you turn off the fireplace, there’s no heat source. As a result, the metal frame starts to cool down and contract. 

If the frame cools down quickly, it also contracts quickly, causing the annoying clunking or snapping sound.

To know for sure that this is causing the noise, take out the metal frame along with the logs the next time you start your fireplace. After it has heated your room, turn it off. If you don’t hear the noise, you can be sure that the metal frame was causing it.

With that said, how can you stop this noise?

If your gas fireplace has a flue, I recommend closing the damper after you turn off the fireplace. 

Sometimes, the cold downdraft from the chimney can cause the metal frame to cool down quickly and make that noise. However, if you close the damper, there’ll be no cold wind, and the frame can contract at its usual rate without making any unwanted noises.

But if that doesn’t work, or if you’re using a vent-free gas fireplace, you can consider getting a frame made of ceramic or other thermally insulating materials.

The Fan Blower Is Dirty

Do you hear a rattling or rumbling noise coming from your gas fireplace for 10-20 minutes after you turn it off?

If yes, it’s likely caused by a dirty fan blower.

Many modern gas fireplaces have a fan blower that pushes the heated air inside the firebox into the room. By design, the blower won’t stop as soon as you turn off the gas fireplace. This is because there’s still some warm air inside the firebox, and the fan blower keeps spinning until it pushes all of it out into your room, at which point it turns off.

If the fan blower gets dirty (which it will eventually), it won’t be able to work smoothly, creating a rattling sound.

Thankfully, you can easily solve this issue by cleaning the fan blower.

To help you out, I’ve put together a detailed step-by-step guide on cleaning the fan blower on your gas fireplace:

  1. Turn off the gas fireplace and switch off the gas supply.
  2. Look into your gas fireplace user manual to know where the fan blower is. It’s usually positioned behind the bottom grill.
  3. Remove the panel covering the blower to access it.
  4. Take a picture of the fan blower to record where all the wires are connected.
  5. Disattach the connected wires.
  6. Unthread the screws and remove the fan blower from its place.
  7. Use a brush to gently sweep off all the accumulated dirt and dust. You can also use a vacuum cleaner. However, refrain from using anything wet, as it might damage the electronic components.
  8. While cleaning the fan, take the vacuum and suck up any dust collected inside the chamber where the fan blower resides.
  9. After cleaning the fan, make sure there aren’t any dents or cracks on it. If there are, replace it with a new one.
  10. Reinstall the fan in the same position and orientation as it was originally. Remember to connect all the wires to their correct points. Look at your previously clicked photo for reference.

The rattling noise should stop after you’ve cleaned the fan blower. However, if it’s still bothering you, it’s time to explore other possible causes.

Wind Is Blowing Down the Chimney

If the gas fireplace is turned off, but you hear windy noises, it’s likely coming from the chimney. This is more so if you own a natural vent gas fireplace connected to a masonry chimney.

As the wind comes down through the chimney, you can hear a whooshing sound or even scratching and banging if there’s something stuck in that area. Moreover, because of the hollow body, a chimney also has excellent acoustic and resonating capabilities. It can often amplify and transport noises from other rooms in your house. 

That said, it’s fairly easy to diagnose if the noises are coming from your chimney. All you need to do is get close to your fireplace and listen to the noise source. 

What’s problematic is stopping the noise.

I’d recommend closing the flue damper and seeing if that reduces the noise to an ignorable decibel. But if that doesn’t help, you can look into installing a chimney balloon.

As the name suggests, a chimney balloon is a small object that fits inside your chimney, which you then inflate like a balloon to cover the chimney hollow fully. It acts as a buffer and effectively stops the wind noises

Moreover, a chimney balloon will prevent cold outside air from coming down the chimney, all the while preventing warm indoor air from leaving your house. This will keep your home warmer, leading to reduced heating bills.

If this has got you interested, here’s a brief 2-minute YouTube video on installing a chimney balloon:

Remember that if you have a chimney balloon installed, you must take it out before turning on the gas fireplace. If you don’t, the balloon will prevent the exhaust smoke from escaping through the chimney, which will then fill your room.

There’s an Insect Infestation

Most of us use our gas fireplace during the winter and keep it off for the rest of the year. This means there’s a dark box with intricate pipework and wires sitting in your home collecting dust for months on end.

Do you know what this kind of environment attracts? You guessed it – insects! In fact, in some situations, even rodents can build their nests inside your dormant gas fireplace.

As these pests start to breed and multiply inside your gas fireplace, they’ll start moving around, which is bound to create noise.

Therefore, if you haven’t serviced or cleaned your gas fireplace in months and haven’t used it for a while, you likely have an insect or pest infestation that’s making all the noise.

You can easily check if this is true by looking around your gas fireplace. 

If you have a bulky arrangement of gas logs, the insects or rodents will likely build their nests underneath it for protection and seclusion. They might also reside inside the piping for the gas supply line or burner assembly.

Now, if you notice an insect infestation inside your fireplace, I strongly recommend you resist your urge to burn the critters. This will create a lot of smoke and might block the piping, creating a host of other problems for your gas fireplace.

Instead, give your fireplace a thorough cleaning using a non-flammable pest repellent. That said, I do understand if you have no interest in messing with insects. In that case, call pest control or your HVAC technician, and they’ll handle the problem for you.

There’s a Gas Leakage

Do you hear a steady hissing sound coming from your gas fireplace? If yes, you could have a gas leak, something which is dangerous, and you should approach with caution. 

First, check if you’ve left the gas supply line open. If yes, turn it off and see if that stops the hissing. If it doesn’t, you might have loose joints or cracks in the pipeline causing the leakage.

But hold on, if there’s a gas leak, shouldn’t you be able to smell gas?

Well, not always! 

The leaked gas might escape through the chimney and thus won’t leave any odor. Therefore, it’s still dangerous and poses a risk of explosion each time you turn on the fireplace.

To stay on the safe side, I suggest checking your gas fireplace with a dedicated tool like the EG Natural Gas Leak Detector (available on Amazon). This tool is portable, can sense all sorts of explosive and combustible gasses, and comes with a sensitivity dial to detect even the smallest gas leaks.

If the device rings an alarm signifying a gas leakage, you should first disconnect the connection between the gas fireplace and the gas supply line. After that, call a qualified technician to diagnose the problem and fix it accordingly.

The Pilot Light Is Burning With a Low Flame

Do you typically keep the pilot light on even when turning off the gas fireplace? Is the pilot light burning with a low flame? If yes, it might be why you’re hearing a hissing noise from your fireplace.

For the pilot light to keep burning, it receives a steady flow of gas. Now, if the pilot light is set to low, most of the gas won’t get burned off, resulting in a subtle hissing noise.

Thankfully, fixing this issue is super simple. 

The pilot light should come with a small screw that lets you adjust the intensity or height of the flame. Fancy gas fireplace models might also have a remote control to adjust the pilot light.

Using whichever method you prefer, increase the height of the pilot light to the manufacturer’s recommended setting. You should find this information in the gas fireplace’s user manual. Generally, the pilot light flame should be around the same height as what you get from a cigarette lighter.

If the hissing noise comes from the pilot light, adjusting its height/intensity should stop the issue.

There’s a Gas Supply Line Blockage

Did you walk into a room and find that the fireplace is making a whistling noise although it’s turned off? 

Well, the fireplace may be turned on but not burning a flame. Instead, it’s making a whistling noise. If that’s the case, there’s a blockage in the gas supply line.

Dust, dirt, and even air can get into the gas supply line and create a blockage that creates a whistling noise and stops the flame production, making it seem that it’s turned off.

Solving the issue can get a bit tricky and dangerous, which is why I recommend calling a qualified technician to help you out.

However, if you feel comfortable and have experience repairing gas appliances, this should be an easy fix. Here’s a step-by-step guide to help you out:

  1. Turn off your gas fireplace and the gas supply. 
  2. Take a flashlight and look inside the gas supply line tube to see if there’s dust inside.
  3. If there’s dust, take a can of compressed air and blow inside the tube to flush out the obstruction.
  4. Recheck if the tube is completely cleared out. If it isn’t, blow compressed air into it again.
  5. When the tubing is clear, turn on the gas fireplace. 

The fire should come up, and the noise should stop.

Key Takeaways

A gas fireplace can make noises even though it’s turned off if it has a dirty fan blower, gas leakage, insect infestation, or a blockage in the gas supply line. Other than that, having wind blowing down the chimney, contracting metal frames, and a pilot light burning at a low setting can also create noise.

Each issue will create a different type of sound, be it rattling, hissing, clunking, clicking, etc. You’ll first need to identify the underlying cause of the noise and then resolve the issue to stop the noise.