Why wont the flame stay on my gas fireplace?

Author: Asia Armstrong  |  Last update: Monday, August 4, 2025

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 does the flame keep going out on my gas fireplace?

Other reasons your gas fireplace may keep going out include a cracked gas line, a faulty thermopile, or a blocked chimney. A cracked gas line may be caused by corrosion of the pipe material to the line. A faulty thermocouple may need to be replaced if it is not sending the correct signals to your gas valve.

What to do if your gas fireplace won't stay lit?

You need to replace the thermocouple and thermopile . Basically the thermocouple senses the flame and keeps the pilot lit and the thermopile produces the voltage to open the gas valve . If the pilot doesn't stay lit it's your thermocouple . You need to replace the thermocouple as cleaning usually doesn't work .

Why is my gas fire not holding a flame?

The major cause of a low flame is a clogged orifice. Spiders climb in when not in use and build webs. When the gas is turned on... the web is blown across the orifice opening. Typically the burner needs to be slid off the orifice for cleaning. Use a very small drill bit or pin or bristle of steel brush.

Why wont my gas heater flame stay lit?

If the pilot light of your gas heater fails to ignite or stay lit, it may be due to a dirty pilot assembly. Over time, the pilot assembly can accumulate dust, debris, or other contaminants, which can obstruct the flow of gas or impede the proper functioning of the flame.

Gas Logs: Flame Won't Stay On - Why?

Why is my gas flame not staying on?

The most common cause of this is dirty or blocked burners, which is the part that you can easily take off to clean.

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.

Should a gas fireplace always have a flame?

The short answer is – you do not need to turn off your pilot light, and there is little risk in leaving it on all summer. Leaving it on is the simpler way to go. But, if you want to turn it off, you can, and there's no harm in that either.

Why won t my fireplace fire stay lit?

Firewood won't stay lit if it's made from softwood. Hardwoods include oak, birch, beech and maple, all dense enough to keep uncannily hot fires going for many hours. Oak is the densest of the hardwoods, generating the most heat for the longest time.

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

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.

Why is my gas fireplace still lit after turning off?

The little flame you see in your gas fireplace after you have turned it off is called a pilot light. A Standing Pilot Light runs constantly, whether your fireplace is on or off. “It's the middle of summer, why do I feel heat from the front of my fireplace?” “Oh well…it's only a little flame, it's no biggy.”

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

Easy DIY Fix: Gas Fireplace Won't Stay Lit
  1. Before You Begin: Is Your Pilot Light Lit Inside Fireplace? ...
  2. The Fix: Pilot Light to Gas Fireplace Won't Stay Lit. ...
  3. Check Your Thermopile Output with the TH/TP Contacts. ...
  4. Don't Replace Your Thermopile or Thermocouple Right Away. ...
  5. Cleaning the Thermopile. ...
  6. Re-test the Cleaned Thermopile.

Why does the fire keep going out in my fireplace?

Your vents are blocked, shut or set wrongly

Every wood burner has air vents that can be used to control the supply of air. As all fires need oxygen to burn, you'll need to have these set correctly at each stage of your fire, to make sure you 'feed it' when it's first set and adjust it when it takes hold.

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.

How do I know if my thermocouple is dirty?

Once you've located the thermocouple, do a visual inspection. You're looking for a few things. 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.

Why does my gas fire keep going out?

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.

Can you replace a thermocouple by yourself?

Replacing a thermocouple is a relatively easy fix that can take less than two hours. This guide reviews how to replace a thermocouple to ensure gas appliances stay in good working order, as well as how to relight a pilot light.

How do I know if I need a new 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.

What are the signs of a bad thermopile?

Symptoms Pilot won't light. Pilot lights but burner won't. System lights, but goes out after a while.

Why does the flame keep going out on my gas heater?

If your pilot light won't stay alight, it might be the thermocouple. Sometimes dust buildup collects on the thermocouple and blocks the sensor. Try cleaning the thermocouple and then relighting the pilot light. If it continues to go out, the thermocouple might need to be replaced.

Why does my gas fireplace always have a flame?

The pilot light isn't just a regular flame; it's a small, continuous flame that stays lit even when the primary gas burner isn't in use. Its enduring nature is crucial to its role in gas appliances. It operates by maintaining a controlled gas flow from the main gas valve.

What is the most likely cause of flames that are lifting off the burner?

Explanation: The most likely cause of flames that are lifting off the burner is improper air to gas mixture. Stoves work on the principle of combustion, and for efficient combustion, a proper mix of air (oxygen) and gas is necessary.

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