Gas Fireplace Pilot Light On But Won’t Start? (We Have A Fix)

Gas Fireplace Pilot Light On But Won’t Start

A fireplace can be a focal point to any room that it is in. There is nothing quite like setting the mood and getting things toasty warm by the fire in the dead of winter. Unfortunately, there are times where the fireplace just doesn’t work.

One of those instances is where the pilot light is on but still won’t light. Always start by checking out the breakers and fuses if you have a modern house. If the power is fine, check the electronic ignition or possibly replace the fuse.

Check the Breaker

For those uninitiated with gas fireplaces, it may sound confusing to hear that there are electronic components within. But the thing is that, even though the fuel source is gas, it still uses an electronic ignition to spark the pilot and start the fire in your fireplace.

The first place to start when your pilot light is on but you’re still not getting a flame is with your breakers and fuses in a modern home. One of the most common problems when a fireplace is not on a loan breaker is overloaded circuitry.

Keep your fireplace on a single breaker if at all possible. Doing so will ensure that the breaker won’t trip and that you won’t blow a fuse, either.

Electronic Ignition

Some but not all of the gas fireplaces out there will come with an electronic ignition. If you’ve checked the breaker and are satisfied, the next place to go is to the electronic ignition check or perhaps a fuse depending on your model of fireplace.

Should you replace one of those components, turn the breaker off all the way and then back on again before trying it out. When in doubt, check out your owner’s manual for specific instructions on lighting the electric ignition through a battery pack if yours has that function.

Spark Ignitor

When your gas fireplace won’t light, but you have a spark ignitor, there are a few things that you can do to resolve the issue. First and foremost, ensure that there aren’t any potential fuel issues keeping your fireplace from lighting.

1. Check the gas regulator. It could be as simple as an issue with the gas regulator that is located at the tank or perhaps a stuck valve. When this is the case, it can reduce the overall reliability of your fireplace as a whole.

2. Try lighting the pilot. Another thing to try is lighting the pilot light yourself if you don’t see a flame.

3. Bypassing the ignition. Check the service instructions that come with your fireplace. There’s a chance that you can bypass the electronic ignition entirely and perform a manual lighting.

Vent Cap

Sometimes it can be as simple as a faulty fireplace vent cap. If a cold draft blows the pilot out on a regular basis, relight the pilot and check out the vent cap. If it continues to extinguish the flame, replace the vent cap; if you don’t have one, call in a service technician to perform the installation.

There are times, however, that the vent cap will not only be present but completely secure. A draft stopper may be necessary to prevent that draft from blowing out the pilot light. And, of course, the pilot light itself could simply blow out.

Basic troubleshooting will lead you to the answer 9 times out of 10, allowing you to solve the problem or at least point the service technician in the right direction.


Another potential issue that can keep your gas fireplace from staying lit is that the thermopile may have gone bad. If the pilot light starts to flicker and looks like it may light but then simply burns out, the thermopile is usually the problem.

Fixing the Thermopile

Unfortunately, when the thermopile goes bad, that’s a repair that has to be performed by a professional service. These components will generally last a couple of years before they burn out and become ineffective; this is entirely due to regular wear and tear most of the time.

Extend the life of the thermopile and your gas fireplace in general by having regular maintenance performed, once a year at least.

Troubleshooting a Fireplace That Stops Working

The thing about gas fireplaces is that they rarely offer a flashing sign that says what the problem is. So, being able to troubleshoot the issue is of the utmost importance. Not only will it help you find the issue, but it will help you to become more accustomed to your gas fireplace.

1. Check the main gas valve. The first thing that you should do is to check the main gas valve. You would be surprised at just how often this is the culprit for a gas fireplace failing to start. The valve can get turned off and forgotten about quite easily.

2. Check the pilot. The pilot light systems are actually the most common reason that gas fireplaces do not light, however.

3. Clear out clogs or blockages. There are also issues with insects and spiders that lay their nests inside of the pilot tubing, particularly in rural areas. For this reason, leaving the pilot light on is the best idea.

Purging the Pilot Tubing

If your gas is on but the pilot hasn’t been lit in at least a few months, you will have to purge all of the air out of your pilot tubing. In order to do this, you will need to hold down the pilot button for anywhere from 1 to 3 minutes; doing so allows the air to bleed out.

Should you notice that there is gas coming out of the pilot but still can’t get it to light, the igniter is most likely the problem.

1. Check for debris. Check for any potential debris that can potentially get between the thermocouple and the igniter.

2. Clear debris.  Clear away the debris and try it again.

3. Checking the thermocouple. Another issue is that the pilot has gas coming out, but it won’t stay lit. If you can determine that the igniter isn’t bad, it is more likely that you have a worn-out thermocouple. Either issue will prevent the fireplace from remaining lit.

How Do You Reset the Pilot Light on a Gas Fireplace?

More often than not, the pilot light can simply be reset in order to get your gas fireplace working properly once again. The process is relatively simple and can save you in a jam.

1. Gas control button. First, hold down the gas control button while also holding the end of your lighter or lit match towards the end of the pilot tube. If done properly, the light should start the instant that the flame is close enough to do so.

2. Hold for 20 seconds. Make sure to hold down the pilot button for 20 seconds or so before releasing it to give the thermocouple the appropriate amount of time to heat up.

What is the Thermocouple?

The entire point of the thermocouple is to keep your pilot lit. The way that this is done is through a tiny electric current that gets sent to a sensor on the gas valve. The current signals to the valve that it should stay open.

The thermocouple achieves this thanks to the probe. The probe has two different metals to it and the voltage gets generated when one of them is heated.

Why Won’t the Thermocouple Work?

Like anything else in this work, the thermocouple can wear down over time and stop working. When the thermocouple does wear down and finally stop working, the pilot can’t remain lit and your fireplace won’t work as it should.

The thing to keep in mind is that the pilot can go out for a lot of reasons that have nothing to do with the thermocouple. Thankfully, there are a few ways to isolate the thermocouple and determine its operational status.

When the Thermocouple Isn’t at Fault

When the pilot doesn’t light at all, it likely is not the thermocouple that is at fault. If the flame lights and only goes out after releasing the gas control knob, however, that’s a prime sign that your thermocouple is malfunctioning.

Before doing anything, look at the pilot flame. If it has a yellow-orange tint to it and looks small, it might be too weak to properly heat the thermocouple. That would be a pilot tube obstruction in most cases.

Test Your Thermocouple

The good thing about most gas appliances is that they all have shared design features. The thermocouple, for instance, will have a probe that is attached to a copper tube. All of these screws into a designated port on your gas valve.

1. Test with a multimeter. When the thermocouple is working properly, you will be able to measure between 30 and 40 millivolts of voltage near the connection portion of the tub with the pilot flame on. Using a multimeter, you can check this for yourself but may need to have a helper to keep the pilot burning as you do so.

2. Unscrew the thermocouple. Unscrew the thermocouple from the gas valve and then set your multimeter to register millivolts.

3. Start the pilot. Start the pilot with your assistant holding the gas control knob in place.

4. Place lead connectors. After a minute or so, place a lead on the connector and the other lead on the shaft of the thermocouple. Anything less than a 25 millivolt reading and the thermocouple will require replacing.

Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

Recent Content