How To Fix It

Gas Fireplace Won’t Stay On? 7 Essential Checks

Gas fireplaces are beautiful additions to any house. They are usually cleaner and safer than traditional fireplaces, thanks to technology, and can be a cheaper and more effective way to heat your home depending on where you live.

The drawback of a gas fireplace is that it can have technical problems you won’t find in a wood-burning fireplace. 

If your gas fireplace won’t stay on, but rather it seems to have a mind of its own, and shuts off by itself, there’s a likelihood that you have a problem with a part of the set-up. The most common issues with a gas fireplace are:

  • Pilot light issues
  • Thermocouple malfunctions
  • Clogged or dirty burner ports
  • Hole or cracks in heating components

(Source: Magic Touch, Gas Fireplace Repair)

No matter what the issue, you can always call a fireplace technician to come out and inspect your fireplace.

Or, if you are more of a DIY person, you can try and figure it out yourself. It may take quite a bit of research on your end, but it can usually help you save some money in the long run. 

Reasons It Can Shut Off

There are quite a few reasons why a gas fireplace can intermittently shut off when being used. However, most people don’t even know where to start looking for solutions, nor do they know how to figure out what the problem is. 

1. Pilot Light Issues

This is one of the first issues that you should check when you are having problems with your gas fireplace.

Gas fireplace won't stay on due to pilot light issue

Without a correctly functioning pilot light, your fireplace won’t stay lit or heat the room effectively.

You want your pilot light to look similar to a blue flame that comes from a blow torch. It won’t be as large as that flame, but the color and shape should be pretty similar. If your pilot light does not look like that, you may have something wrong with it. 

Pilot light closeup

2. Dust in The Pilot Assembly

The pilot light is an essential component in keeping your gas fireplace lit and working well; it may even be one of the most important things.

Have a Question? Ask HVAC Technician

Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.

So, it goes without saying that if something is wrong with your pilot, or the pilot assembly, your fireplace won’t function correctly.

Pilot light assembly

One of the more common issues with the pilot assembly is that there is a build-up of dust in it.

If that happens, the flame is almost lifted away from the pilot area and causes it to shut off. Some people call it a lazy flame due to it not being strong enough to stay lit. 

3. Thermocouple Sensor Issues

On a gas fireplace, you will have a thermocouple that helps to regulate temperature by keeping the pilot light at a certain height and temperature.

Gas fireplaces have thermocouple sensors on them for a couple of reasons:

  • To allow you to control the temperature of the room.
  • To keep the fireplace from becoming too hot and causing dangerous situations.

The thermocouple will not allow your fireplace to get past certain temperatures for safety reasons.

Gas fireplace won't stay on due to burnt thermocouple

If it malfunctions, it will likely not stay lit for an extended period of time. Some gas fireplaces have a thermocouple and a thermopile.

A thermopile is essentially the same thing; however, a thermopile usually cannot conduct the amount of energy that is needed to fuel the fireplace.

If your fireplace has both of these, either one or both could be bad. It also may be time for an upgrade if you are consistently having problems with it. 

4. Oxygen Sensor Issue

Most gas fireplaces have oxygen sensors that aim to make sure there is a sufficient amount of oxygen in the room.

If your oxygen sensor is faulty, it will likely think that there is low oxygen in the room and turn your fireplace off.

Ignitor, pilot light, and thermocouple closeup

With most gas fireplaces, this is an easy fix, merely replacing the oxygen sensor allows you to remedy the issue and keep your fireplace on.

However, depending on how old your fireplace is, this can become a challenging and costly fix. 

5. Incorrect Gas Pressure

The gas line that you have connected to your fireplace is supposed to keep a certain amount of pressure within the gas line that connects to the pilot assembly. 

Without proper gas pressure, the pilot light will either not stay lit or cause the fireplace to shut off for safety reasons. 

Thankfully, most of the time, this is an easy fix. A fireplace technician can come in, and they have a tool called a manometer that measures gas line pressure.  They can then calibrate it or fix whatever the issue is. 

After that, your fireplace should stay lit more consistently as long as that is the only problem you have. If fixing any issue doesn’t help your fireplace stay lit, it is likely that you have more than one issue. 

6. Clogged or Dirty Burner Ports (gas fireplace won’t Stay On)

The locations where the flames come out of a fireplace are all called burner ports. If any of these are clogged or dirty, they can cause the flame to go out, which will also cause your fireplace to shut off. 

Gas fireplace burner ports

Through regular use, or long periods of inactivity, the burner ports can become dirty and clogged with dust or carbon deposit build-up; this will not allow gas or the flames to get through enough to stay lit.

The best way to keep this from becoming an issue is to regularly get your fireplace professionally cleaned and inspected.  However, if you want to put in a little elbow grease and spend some time learning, it is not difficult to do yourself.

7. Cracking or Breaking

Something that can be almost unnoticeable can cause issues that make your fireplace unusable.

If any components have holes, cracks, or broken pieces, it may be the reason for your issues.

While checking for other problems, or while cleaning your fireplace, always check for holes or damaged things.

Not getting these issues fixed as soon as possible can cause significant issues down the line that could cost a large amount of money or even cause injuries. 

(Source: Den Garden, Kozy Heat, Magic Touch, Gas Fireplace Repair)

Safety Tips For Cleaning A Gas Fireplace

Most of the time, if your gas fireplace won’t stay on, cleaning it will fix the issue.

Now, it is always safer to hire someone to do this for you, but if you prefer to do it yourself and save some money, there are a few safety things to keep in mind. 

1. Always Turn Off the Gas

If the gas is on while you are cleaning it, you can risk a gas leak or an ignition from the heat that can be catastrophic.

Gas valve in ON position

It isn’t likely that you would notice a gas leak while you are cleaning it until it is too late. 

Once you turn off the gas, always wait until the pilot light is entirely out before you begin to take anything apart.

This ensures that all the gas from the line is burnt out, and you should have no issues when you clean it. 

2. Gently Disassemble

While you are taking your fireplace apart, it is important to be very gentle when taking things apart.

If it seems like it is harder to take apart than you think it should be, do some research to double-check that it is supposed to come apart. 

You can save money while cleaning your fireplace by yourself, but if you break it, you stand a good chance of paying more money to have someone fix it. 

3. Don’t Use Spray Cleaners

While it makes sense to spray the components down and scrub them with a brush, this can actually be very dangerous, especially when you go to turn your fireplace back on.

If cleaners or water get into the gas lines, they can cause explosions or larger fires than are safe.

Simply scrub the components with a dry brush and vacuum up the dust and debris that falls off. This should take care of most, if not all, the build-up and dust that can be a hazard. 

4. Inspect While You Clean

While you are cleaning your fireplace, inspect every individual component that you touch for any cracks, holes, or breakage. Any of these issues can cause issues such as:

  • Gas line leaks
  • Pilot light issues
  • The inability of your fireplace to stay lit.
  • Fire hazards

If you notice any of these issues, immediately turn off the gas and call someone to properly repair the problem. Anything that can lead to leaks in a gas line is nothing to procrastinate about. 

(Source: The Spruce, Scan An Energy)

Final Thoughts

Keeping a gas fireplace up and running is not a terribly difficult task. Merely keeping a good routine of upkeep can keep a fireplace going for quite a few years, even decades or more.

However, when having problems with your fireplace, it’s always best to get it fixed as soon as possible. 

If your gas fireplace won’t stay on, it can be frustrating while trying to figure out why the problems are occurring. You can always do more research…. or call a professional to come out and find and fix the problem much quicker.

Leave a Comment