What causes a gas fireplace pilot to go out?

Author: Rose Willms  |  Last update: Tuesday, December 23, 2025

Some of the possible serious reasons for pilot lights to go out include loose or broken gas valves, thermocouples or heat exchangers, faulty venting, low gas pressure, or high winds. If you believe there is a serious problem, don't hesitate to contact a professional.

Why does the pilot keep going out on my gas fireplace?

If your gas fireplace pilot light keeps going out, you may have a problem with faulty pilot controls. The pilot control failing due to age or a mechanical issue can cause your pilot light to keep going out and prevent it from being relit.

How do you fix a gas fireplace that keeps going out?

Turn the gas off at the fireplace! Verify the pilot flame is out!!! You will have to clean the pilot orifice. How? You take a can of compressed air and blow out the area where the pilot flame comes out. 90% of the time this fixes the issue. (Don't be surprised if you find someting blocking the pilot.)

Why does my gas fireplace go out by itself?

Thermocouple and Thermopile Issues

Over time, these components can get dirty or fail, causing the gas fireplace to shut off abruptly or prevent it from staying lit. Cleaning or replacing the thermocouple or thermopile can often solve this issue.

How do I know if my thermocouple is bad on my gas fireplace?

Use an electric meter on volts DC to test if the thermocouple is bad. you can also try to re-light the pilot and see if it goes on. Thermocouples can be cleaned, but this is only a short fix. The pilot will go out again over time. Thermocouples are not expensive. The best thing to do is just change it.

TOP 10 Reasons Why the Gas Pilot Light Goes Out & Won't Stay Lit!

How do I know if my thermocouple needs replacing?

The best way to verify that you need a new thermocouple is to see if your pilot light is lit. If the pilot light can't hold ignition, that means either a problem with the gas supply or, more likely, the need for thermocouple replacement.

How long does a thermocouple last on a gas fireplace?

Thermocouples can last up to 10 years if properly installed and maintained, while furnaces can last 15-20 years, although either may wear out sooner in multifamily units.

What is the most common problem with gas fireplace?

One of the most common problems faced by homeowners with gas fireplaces is the pilot light going out or not staying lit. The pilot light is a small flame that ignites the gas burner, which produces the heat for your fireplace — if the pilot light goes out, your fireplace won't work.

Why does my gas fireplace go out after a few minutes?

Your gas fireplace could be turning off for several reasons. The most like culprits are likely tied to some kind of problem with your setup. Anything from issues with your pilot light, clogged ports on burners, damage to heating components, and thermocouple/thermopile malfunctions can be to blame.

Why wont my gas fireplace stay running?

A gas fireplace that won't stay lit is often caused by a faulty thermocouple, an insufficient gas supply, or a blocked pilot light. Regular cleaning and inspections can often help.

Why does my gas flame keep going out?

There are many reasons why a gas stove would stop working, such as the gas or power going out, food debris clogging the igniter, or a broken spark module. Schedule a service professional to assess your gas stove.

How much to replace a thermocouple in a gas fireplace?

Fireplace thermocouple replacement costs $150 to $350 total.

How do you fix a pilot light that keeps going out?

How To Re-Light A Furnace Pilot Light ?
  1. Step 1: Review Furnace Manual. ...
  2. Step 2: Identify Pilot Light. ...
  3. Step 3: Turn OFF Gas. ...
  4. Step 4: WAIT 5 Minutes, then Turn Gas to "Pilot" ...
  5. Step 5: Hold Reset Button. ...
  6. Step 6: Press The Igniter While Holding The Reset Button. ...
  7. Step 7: Turn Gas to "ON" position.

Why does my gas fire go out after 20 minutes?

Low gas pressure or a faulty gas valve can interrupt the gas supply, causing the fire to burn out. If you can smell gas near the fire, hear hissing sounds, or the gas leak detectors activate, you must contact a professional right away to check for safety.

What does a damaged thermocouple look like?

Failed Thermocouple Symptoms

The first is signs of contamination on the tube, which can include discoloration, cracks, or pinholes. Next, check the wiring for any signs of wear or corrosion like missing insulation or bare wire.

Can you clean a thermocouple without removing it?

Clean the thermocouple - using the emery cloth sandpaper, sand the ends of the thermocouple and then give it a finishing touch with the lint-free cloth. Hopefully, you can get to the ends of the thermocouple without having to detach it from the assembly, but you may have to do that.

Why wont the pilot light stay on my fireplace?

The Fix: Pilot Light to Gas Fireplace Won't Stay Lit

This can be an indication that your fireplace thermocouple is either bad or worn out. However, if your pilot is lit but the gas fireplace isn't, then there's probably a problem with your thermopile.

Why is my fireplace pilot light flickering and going out?

If the flame of your pilot light is faint or flickering, you may need to find your pilot's adjustment screw and increase the flame's intensity. If it's yellow instead of blue, you probably don't have the pilot's temperature correctly set, which may also send a bad signal to the thermocouple.

What is the lifespan of a gas fireplace?

But in general, an efficiently running modern gas fire kept clear of dust and debris should hit or exceed that 10 to 15-year mark before showing signs of wear. Older or cheaper models may start to struggle after 7–8 years. Regular servicing and maintenance will be essential to maximising lifespan potential.

How do you fix a gas fireplace that won't ignite?

How to Troubleshoot a Gas Fireplace
  1. Make Sure the Gas Is On. The first thing you should do if your gas fireplace won't turn on is check that the gas is actually on. ...
  2. Give Your Gas Logs a Thorough Cleaning. ...
  3. Purge the Air Out of the Pilot Tubing. ...
  4. Test the Thermocouple. ...
  5. Check the Spark Igniter.

What are the symptoms of a bad thermocouple?

When you have a thermocouple that is going bad on your water heater, the most obvious sign will be a pilot light that always seems to be going out. If you light the pilot light but then find it extinguished less than a week later, you'll need to closely examine the thermocouple.

Why did my gas fireplace pilot go out?

Some of the possible serious reasons for pilot lights to go out include loose or broken gas valves, thermocouples or heat exchangers, faulty venting, low gas pressure, or high winds. If you believe there is a serious problem, don't hesitate to contact a professional.

How do I know if my gas fireplace thermocouple is bad?

Common Signs of a Failing Thermocouple

Here are some common indicators: Difficulty Lighting the Fireplace: If you struggle to light your fireplace, or if it takes several tries to keep the pilot lit, it could suggest that the thermocouple is not sensing the flame correctly and is failing to keep the gas supply open.

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