How to Fix a Gas Fireplace That Keeps Turning Off (Easy DIY Fixes)

There’s nothing quite like relaxing by a cozy and warm fireplace at home with your loved ones. Occasionally, you may experience problems with the gas fireplace refusing to stay on. This does not always require help from a trained professional, and can sometimes be fixed through easy DIYs. 

The most frequent cause of a gas fireplace turning itself tends to be the pilot light. Thankfully, the gas fireplace is notoriously known as an appliance that is easy to fix as a non professional. Before you begin, round up some basic tools such as a voltmeter, compressed air, a flashlight, and a pipe cleaner. 

This appliance is both fashionable and functionable, perfect for enjoying on those cold winter nights. When it begins interrupting your comfort by shutting off, you will want to find out why. Continue reading to find common causes of your gas fireplace turning off and how to fix it. 

Why is this Happening?

A common reason that your gas fireplace could be shutting itself off is because of your pilot light. With this in mind, There are many different reasons as to why your gas fireplace could be turning itself off.

You will need to learn each piece and their function to check individually for the faulty component. These are some reasons as to why this may be occurring and what you can do to fix it. 

The most common reason that your fireplace could be turning off is the pilot light. This can sometimes malfunction. If it is the pilot light, most times you will simply need to reset it and that should solve the problem.  

If it isn’t your pilot light, you will move on to checking the thermocouple, thermopile, and oxygen sensor.

The thermopile should be checked first to ensure the valve is allowing gas to flow in. Next, inspect the thermocouple with a multiuser. You will then review the oxygen sensor to verify it isn’t automatically shutting down the system.  

Another common reason your gas fireplace may continuously turn off is from blockages. If there are any blockages or dirty ports it will prevent the fireplace from functioning properly. Cleaning these will give you insight into whether or not this is the culprit. 

The Parts of a Gas Fireplace 

Learning the different parts of a gas fireplace is important before you get to work fixing it. If you do not completely understand a part, it may not get fixed properly, prolonging the problem. The last thing you want to do is break another part while trying to fix another.

Pilot Light

The pilot light is a common problem as to why gas stoves and fireplaces automatically turn off. This component is a small light that needs to stay lit in appliances that are gas fired. Appliances that use pilot lights can include your furnace, water heater, and gas fireplace. 

When the appliance is powered on, gas is funneled through to the main burner. The pilot light can then ignite the gas to turn on your appliance, and in the case of your fireplace, your heat. Pilot lights can go out occasionally from drafts or improper ventilation, but if it happens continuously, it could be your thermocouple.

Oxygen Sensor

This part of a gas fireplace is usually only found exclusively in ventless gas fireplaces. Due to ventless gas fireplaces not venting the waste air out, they must have the capability to burn clean. The by-products emitted out must be safe to put back in the room. 

The oxygen sensor provides an important role for the fireplace. It must be included to monitor the oxygen levels in the room to make sure they do not go below a certain level. If the level goes too low, the fireplace should shut itself off as a safety precaution. 


The thermocouple is the part of the gas fireplace that measures temperatures. It is made of two different metals joined at the end. When the connecting part of the two metals become hot or cool, voltage is created and this helps to correlate back to temperature. 

This component has a relatively low cost and a simple sensor used in many different temperature measurement processes. They are used in a plethora of different applications. 

It is important to learn the structure and functionality to figure out the correct thermocouple type and material. This is to make sure the thermocouple is fixed correctly. 


The thermopile is an electronic device that is made of multiple thermocouples in a series. The thermopile works hard to convert thermal energy into electrical energy. Its purpose is to create a voltage when different metals become exposed to temperature differences. 

The thermopile can create electrical energy from the heat given off by the gas fireplace. Its temperature sensor is non contact and uses infrared radiation to measure temperatures. 

It is both larger and thicker than the thermocouple. It typically has more voltage output than an average thermocouple. The thermopile can usually be found near the pilot assembly and connects to the gas valve

Gas Line

It is crucial to take care when handling the gas line. This is the transportation of highly flammable gasses to different appliances that use fire. Anything having to do with the gas line should be dealt with by a licensed professional. 

The professional will find a location with few twists and turns to avoid hazardous gas buildup. Measurements will be taken and the site prepared to follow safety regulations. The line is run to the location of the fireplace. 

Finally, the fittings are attached to the fireplace and the gas is turned on to make sure everything is sealed properly. 

Heating Elements

The heating elements are other miscellaneous parts that make up your gas fireplace. This includes the firebox, faux media (coals or logs), burner, controls, and more. These parts work together in harmony to allow the fireplace to run efficiently. 

Each part plays a specific role to give you the comfort of warmth. The faux media, whether it be coals or logs, is what gives you the aesthetically pleasing view of an indoor fire. The firebox is a combustion chamber where the fire is ignited. 

This is just a quick overview as there are many different parts that make up the gas fireplace.

You will check each part listed in this article until your gas fireplace stays on. Make sure you have your voltmeter, compressed air, a flashlight, and a pipe cleaner close by before you begin. To maintain your own safety, the pilot light should be out when you are looking over your gas furnace.

Troubleshooting A Gas Fireplaces That Keeps Shutting Off

Check or Replace the Pilot Light

For your safety, the gas should be shut off before replacing the pilot light. You will find a bracket behind the pilot light that you will unscrew. 

Then, disconnect the wires from both ends. You can discard the old piece and grab your new one. Before you do this, though, it may be helpful to take pictures before unplugging.

You will then match up the wires to the correct spots and tighten them in. Once all the wires are hooked up right, go ahead and screw the bracket back on. Relight your pilot light and let it run a few minutes to see if it works. 

Test and Replace the Thermocouple Sensor

The thermocouple should be clean from buildup as well as the pilot light having a strong blue flame before testing. 

If the flame is weak or there is debris on the thermocouple it could cause a low reading. Your voltmeter should be set at DC (Direct Current) volts.

The thermocouple should then be removed from the gas valve and take the readings from the end of the thermocouple. 

The readings should be between 7mV-30mV, if it is under 7mV the thermocouple should be replaced. Because the thermocouple is already unhooked to take the readings, a new one can be put in if needed. 

Test and Replace the Thermopile Sensor

You may be thinking, “I’m not a professional, I can’t change my thermopile!” I assure you, it’s easier than you think. You will turn off the gas for your safety and take the thermopiles out of the gas valves. Grab a hold of your new thermopile and simply switch it out! The white and red wires should hook up to where they were previously. 

To see if it worked, flick on the pilot light and let it warm up for a little bit. Once it is warmed up, you are going to pull out your voltmeter. If it is over 500 millivolts, it was successfully replaced.

Clean the Oxygen Sensor 

Before you start, turn off the unit including the pilot light and let cool for 30 minutes. Take out your logs or coals. Then, you will inspect the burner, pilot, and primary air inlet holes found at the end of the burner tube for any debris such as dirt or lint. 

You will then use the compressed air to clean the different ports, holes, and slots of the burner. The primary air passage can be found at the end of the burner and should be free of any large particles. This can be cleaned using the pipe cleaner. 

You Need Your Chimney Swept 

Regardless of if you use your gas fireplace or not, it should be receiving a chimney sweep and inspection annually. The type of fuel burned does not matter as there is still fire occurring in your living room. The yearly inspection ensures that the firewalls can properly contain the fire and then safely dispose of the exhaust. 

The chimney should be both cleaned and inspected by professionals. This guarantees that the appliance is in good standing and safe for continued use. Some may try to do this themselves, but the professionals not only have the equipment, but the knowledge to keep you safe. 

 Check Your Gas Pressure

On your rating plate you will see what value your supply and manifold pressure should be. The ports to check them are near the gas supply. You can find the supply port towards the front and the manifest towards the back. 

Find your handy flathead screwdriver and turn it counter clockwise in the port. Grab your manometer and put it on the port to get a reading and do this with both ports. When you test your gas pressure, make sure you turn on all other gas appliances in your home for accurate readings.

When To Call a Professional

In many cases, it is possible to DIY fix your gas fireplace. Doing it yourself will save you time and money. Before beginning, you will have to learn every piece inside to ensure you are not disrupting the working parts. 

While it is possible to fix your gas fireplace yourself, there are situations where the work should be left for a professional. When inspecting your fireplace and you notice the smell of rotten eggs or hissing noises, a professional must be called. This could mean a natural gas leak and is a blowout risk. 

Some other signs that it is time to call a professional is if the pilot light won’t come back on. The pilot light should come back on after some simple solutions, but if not, it could be a more serious problem. Another sign is a burning smell as this is a sign of dirt and debris. 

Professionals will be more than happy to inspect your gas fireplace if you are unsure about the problem.

On average, you can expect to spend between $75-$100. If the professional needs to repair the fireplace, you may be spending between $200-$1000 dollars. The price can vary by geographic location.


It can be frustrating when your gas fireplace isn’t working as it should. Thankfully, there are plenty of things you can do to troubleshoot the problem. If you end up needing the help of a professional, ask for a quote to avoid being surprised by the cost.

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