Gas Fireplace Pilot Light On But Won't Start? (We Have A Fix)
More and more homeowners these days are choosing gas fireplaces over traditional wood fireplaces due to their convenience. The truth is both types can make for a great focal point to any room. Unfortunately, gas fireplaces still come with their downfalls. One of the most common issues people deal with is when their gas fireplace won’t start but the pilot light is on.
So, what gives?
If the fireplace pilot light is on but won’t start, make sure your gas valve is turned on and check the fuse or breakers. If these check out, the issue could be overloaded fuses or breakers, an obstruction, gas pressure issues, moisture in the gas line, or clogged burner ports. Bad thermocouples or electric ignition can also cause a problem.
A fireplace that won’t light doesn’t do anyone any good, so what can you do to fix the problem? Use this handy troubleshooting guide to get to the bottom of the problem, and you’ll have a roaring fire in no time.
Possible Reasons Why the Pilot Light is On but the Fireplace Won’t Start
The thing about gas fireplaces is they rarely offer an obvious sign that says exactly what the problem is. So, being able to troubleshoot the issue is of the utmost importance. Not only will this help you find whatever is going wrong, but it will help you to become more accustomed to your gas fireplace.
There are several reasons your gas fireplace pilot light is on but won’t start the fireplace. The best thing you can do is start with the simplest solution: make sure your gas valve is turned on.
If the main gas line is off for some reason, your gas fireplace won’t light, even if the pilot light is on. Should you notice your gas line is on, but you are experiencing issues with it, don’t hesitate to call someone. A fault with the gas line can be a major hazard and should be handled by a professional.
Once you’ve ensured the main gas line is on, you can start troubleshooting all the other possible reasons your gas fireplace won’t start. Here’s a list of the different gas fireplace components you should check to identify the issue:
- Pilot Light
- Electronic Ignition
- Spark Ignitor
- Vent Cap
- Obstructions Near Pilot Light
- Issues in Gas Line
- Burner Ports
1. Reset the Pilot Light
The pilot light system is actually the most common source for issues occurring when a gas fireplace pilot light is on but won’t start. So, even if the light itself seems to be working, you’ll want to take a look at it to make sure there’s not a deeper issue. Luckily, checking the pilot light can be a fair easy and straightforward fix.
More often than not, you can simply reset the pilot light if the fireplace pilot light is on but won’t start.
The process is relatively simple and can save you in a jam. Here’s what you have to do:
- 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.
- Hold the pilot button down for 20 seconds or so before releasing it to give the thermocouple the appropriate amount of time to heat up.
2. Check the Breaker
If the pilot light and gas valve are on, but you’re still not getting a flame, you should check the breakers and fuses. When a fireplace is not on a lone breaker, it can cause the circuit to overload.
The best thing you can do when you have a gas fireplace is keep it on a single breaker if possible. Doing so will ensure that the breaker won’t trip and that you won’t blow a fuse either.
For those unfamiliar with gas fireplaces, it may sound confusing to hear that they have electronic components within. Even though its fuel source is gas, it still uses an electronic ignition to spark the pilot and start the fire in your fireplace.
3. Look for a Faulty Electronic Ignition
Some but not all of the gas fireplaces out there will come with an electronic ignition. That said, the next place to check said electronic ignition or fuse.
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.
4. Or a Faulty Spark Ignitor
If the fireplace pilot light is on but won’t start and there is a spark ignitor present, there are a few things that you can do. Here are the steps you can take to see if there’s an issue with the spark ignitor:
- Ensure that there aren’t any potential fuel issues keeping your fireplace from lighting.
- Check the gas regulator that is located at the tank or look for a stuck valve.
- Try lighting the pilot if you still don’t see a flame.
- Check the service instructions that come with your fireplace to see if you can bypass the electronic ignition entirely and perform a manual lighting.
5. Check for a Faulty Vent Cap
Sometimes if the gas fireplace pilot light is on but won’t start the fireplace, the issue 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. Should it continue to extinguish the flame, replace the vent cap altogether.
Call in a service technician to perform the installation if you don’t have one and don’t know how to do it yourself. In other situations, 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 one of these answers 9 times out of 10, allowing you to solve the problem or at least point a service technician in the right direction.
6. Examine the Thermocouple or Thermopile
Another potential issue that can keep your gas fireplace from staying lit is that the thermocouple or thermopile may have gone bad. A thermopile is a series of thermocouples connected together.
The entire point of the thermocouple is to keep your pilot lit. The way it does this 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, which has two different metals attached to it, and the voltage gets generated when one of them is heated.
When the pilot doesn’t light at all, it likely that the thermocouple is not at fault. On the other hand, if the pilot light starts to flicker and looks like it may light but then simply burns out, the thermopile is usually the problem.
Unfortunately, when the thermopile goes bad, the repair should only be performed by a professional. These components will generally last a couple of years before they burn out and become ineffective.
This burn-out is generally due to regular wear and tear. 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.
To extend the life of the thermopile and your gas fireplace in general, you should have service technicians come in to perform regular maintenance checks. You should plan to do this at least once a year.
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.
Testing 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.
- 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.
- Unscrew the thermocouple. Unscrew the thermocouple from the gas valve and then set your multimeter to register millivolts.
- Start the pilot. Start the pilot with your assistant holding the gas control knob in place.
- 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.
7. Clear Obstructions Near Pilot Light
There could be debris or trapped insects blocking the pilot light. This can be the case especially if you haven’t had the light open for a while. Check the area to make sure it is clear.
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.
Here’s what you should do:
- Check for any potential debris that can potentially get between the thermocouple and the igniter.
- Clear away the debris and try it again.
- Check the thermocouple.
8. Look for Issues in Gas Line
There is also the possibility that you don’t have adequate gas pressure to light the fireplace or there is moisture in the line. Either of these situations will cause the gas fireplace to not light. Call a professional to assess and remedy either of these issues.
9. Unclog Burner Ports
If the fireplace won’t start or your pilot light is flickering on and off occasionally, you could have clogged burner ports.Insects and spiders may lay their eggs inside of the pilot tubing. This is particularly common in rural areas. For this reason, leaving the pilot light on is the best idea.
You may need to clean them to resolve the problem. Check for blockages, dust, debris, etc., and clean the burner ports.
Can you jumpstart a gas fireplace?
Turn your knob on the fireplace from off to “pilot.” Push the pilot knob in to send gas into the system. then push the igniter button once every second. Do this until it lights. If you haven’t used the fireplace in a while, you might need to do this several times before it lights.
Can you leave the gas fireplace pilot light on?
It’s actually recommended to leave your pilot light on during the fireplace season. It can help deter bugs and other blockages. However, to save energy and money, most professionals recommend turning the pilot light off seasonally. However, make sure your gas fireplace is designed to keep the pilot light on. Not all fireplace models have a “standing” pilot light, or one that remains on constantly.
Our Final Thoughts on Fixing the Issue with Your Pilot Light and Fireplace
At the end of the day, many things that can be the root cause of when your gas fireplace won’t start but the pilot light is on. The good news is, that means there are plenty of ways to troubleshoot the issue as well. If you still can’t seem to fix it after trying everything, all is not lost. You are always able to get in touch with a service technician and have them look over your fireplace.
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.
More by Ryan Womeldorf