Why wont my pilot light stay lit in my fireplace?

Author: Troy Ullrich  |  Last update: Sunday, June 21, 2026

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 won't my pilot light in my fireplace stay lit?

Most of the time the reason a pilot wont stay lit is that the pilot orifice and pilot burner are dirty and need to be cleaned. Clean those first before doing anything else. It's routine maintenance that needs to be done in any case.

Why does the fireplace pilot light keep going out?

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.

What do you do if your pilot light 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 igniting but not staying on?

There are many possible reasons why the burner will not stay lit - the gas jet may be blocked, the valve may be set too low, the air flow may be restricted, there may be an issue with the pilot light, and so on.

GAS FIREPLACE PILOT LIGHT WON'T STAY LIT - EASY FIX

How much to replace a thermocouple in a gas fireplace?

Fireplace thermocouple replacement costs $150 to $350 total.

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.

How to tell if a thermocouple is bad?

There's really just one telltale sign of letting you know when the thermocouple isn't working, and that's when the pilot light won't stay lit. If you experience this problem, it's important to have your thermocouple assessed as soon as possible.

Why wont the flame stay lit on my furnace?

Faulty or dirty flame sensor

If the flame sensor gets a layer of grime over it or becomes faulty, it may mistakenly shut off the gas even though the burners ignited. Professionals can clean or replace the flame sensor to correct this.

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.

Should gas fireplace pilot light stay on?

In the end, keeping the gas fireplace pilot light on or off is a personal preference. The decision boils down to residual heat, gas usage, and the possibility of nesting spiders. Generally, we recommend turning off the gas pilot light during the summer months.

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

A faulty, misaligned, dirty, or damaged thermocouple is often the culprit behind your pilot light going out. The thermocouple is an automatic safety shutoff device that prevents the gas valve from opening if the pilot light is out.

What is the most common problem with a 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 wont the pilot light stay lit on my gas 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.

How do 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.

Is it hard to replace a thermocouple on a gas fireplace?

Thermocouples are designed to detect a pilot light's loss of heat and close the gas valve to prevent a gas leak. Replacing a thermocouple is a relatively easy fix that can take less than two hours.

Will a pilot light stay lit with a bad thermocouple?

The Pilot Lights But Won't Stay Lit

If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds, that's the sign of a thermocouple malfunction.

How do I know if my thermocouple needs replacing?

Failed Thermocouple Symptoms

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.

How much does a thermocouple cost?

Furnace Thermocouple Replacement Cost

If you're comfortable handling small furnace repairs, you can purchase a furnace thermocouple for about $10 to $20 from a hardware store or online. Replacing the thermocouple requires some basic tools and familiarity with the furnace's inner components.

Why is my gas heater igniting but not staying on?

Faulty thermocouple

If the gas furnace pilot light won't stay lit, the thermocouple will shut down the gas valve, so gas cannot be released into the home. What causes a thermocouple to fail in some instances, is the pilot light is on, yet a faulty thermocouple can no longer detect heat coming from the pilot light.

Why wont my pilot light stay lit when I release the knob?

The flame will go out if you release the knob before it is hot. The thermocouple can become dirty and caked with grit, preventing it from heating up and detecting that the pilot is lit. As a result, the pilot will always go out after you release the reset button.

Why does my furnace only stay lit for a few seconds?

If the burners visibly ignite, but then go out after approximately 6 seconds, this may indicate a dirty flame sensor. Multiple failed ignition attempts will typically generate an "Ignition Failure" diagnostic on the ignition control board.

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