Gas Fireplace Wont Light – Diagnoses and Troubleshoot in One Easy Guide

It’s all cold and you’re just coming home from work, and the temperature inside the house isn’t as warm as you thought it would be.

There’s something wrong with your fireplace then, and most probably the gas fireplace wont light instead of warming your house beforehand.

On another occasion, you’re visiting your parents and hoping for a family reunion, and then the gas fireplace wont light for some reason, that may mess things up for all of you, won’t it?

Don’t worry, this WarmthPedia guide will help you diagnose, troubleshoot, and fix the situation when your gas fireplace wont light for any reason.

We’ll provide you with the potential causes, and how to deal with each one, and then we’ll teach you how to troubleshoot them in a step-by-step manner.

Gas Fireplace Wont Light: What Are the Potential Causes?

The aforementioned situations are unfortunate, but you control your fortune when it comes to gas fireplace problems with the help of this WarmthPedia guide, the same as we help you deal with awkward smells it could produce.

However, a gas fireplace wont light problem can be caused by a handful of errors, issues, and dysfunctioning components.

Here are the potential causes of a gas fireplace that doesn’t light properly:

1. Gas fireplace’s components are dirty.

2. Pilot Light doesn’t work.

3. Overloaded circuit with a line that isn’t supplied with gas.

4. Dead batteries in the remote control.

5. A broken wall switch.

6. Connections are loose.

7. Valves are defective.

8. Thermocouple is broken.

Gas Fireplace Wont Light

Gas Fireplace Wont Light: Troubleshooting the Problem

Before you troubleshoot any problem associated with your gas fireplace, you should know exactly how does a gas fireplace work, and learn more about its anatomy.

Now, here’s a step-by-step guide on the troubleshooting “Gas fireplace wont work” problem:

a. Always make sure the gas is put ON

It goes without saying that your gas fireplace wont light when there is no gas, right?

Sometimes you just forget to put it ON, other times a family member just feels it’s warmer than they need and would go and turn it off.

No gas fireplace runs without gas, make sure you turn it ON, and then take a look at the main gas valve and make sure it’s functioning properly.

b. Empty the Air out of Pilot Tubing

Sometimes the air stuck inside the pilot -since it hasn’t been lit for months during summer and spring- can get in the way of a natural gas flow inside the pilot tubing.

To fix this issue, your goal would be to empty out the air by purging it out of the tubing by holding the pilot button for a couple of minutes.

Here’s how to light pilot light on gas fireplace for additional value.

c. Check for a Potential Spark Ignitor Issue 

The gas is on, and the pilot tubing doesn’t have air stuck in there, so the movement of gas through the pipes from the source is alright.

Now, check for a potential issue with the spark ignitor, since it could be the problem by not igniting the gas.

The troubleshooting starts by vacuuming/cleaning debris stuck between the spark ignitor and the thermocouple.

Some would advise blowing compressed air into the pilot area, but we’d like to keep the air out of the whole area.

d. Thermocouple Worn Out

If all the 3 aforementioned issues aren’t issues anymore, and the gas fireplace wont light, then it has to be the thermocouple.

Most of the time the thermocouple can be worn out, and cleaning the debris around it isn’t enough.

Therefore, the thermocouple will keep the gas line closed regardless of how heated up it is.

According to our professionals at WarmthPedia, local professionals can help you get the worn-out thermocouple going easily.

However, we asked a couple of professionals and they asserted that it’s easier to clean out and deal with worn-out components when the burner assembly is removed.

e. An Overloaded Circuit

The overloaded circuit is easier to deal with since you’ll only need to reset the breaker by flipping it on and off.

Generally speaking, an overloaded circuit can stand in the way of turning any heating system on, as it works as a safety procedure.

f. Deal with the Remote Control or the Broken Wall Switch

If the whole internal system of the gas fireplace is working properly, then it may not be receiving the order to light the gas up and start heating.

It’s also an easy fix, replace the batteries inside the remote control, and make sure it’s sending the signal and orders to the fireplace.

The same goes for the broken wall switch.

Cleaning Gas Fireplace Components

Debris and dirt can be among the most famous trouble-makers when it comes to a gas fireplace that won’t light.

Therefore, we present you with the most accurate way of cleaning gas fireplace components, so your thermocouple and pilot light have an easier time functioning.

If your gas fireplace has fake logs then you’ll need to remove them for easier access.

Start by vacuuming the gas fireplace to remove any loose debris or ashes.

A vacuum can be of great help when you have an outdoor gas fireplace or fire pit since it’s susceptible to more debris outside the house.

Now, get a wire brush and start cleaning carbon residue from the following components in the same order:

Start with Pilot Light, then gas openings, thermocouple, and then finish with the thermopile leads.

We find it more convenient to use both the vacuum and the wire brush, to help get rid of both the debris and the residue.


This concludes WarmthPedia’s guide on helping you diagnose and troubleshoot the gas fireplace wont light problems.

If this guide has helped you, please tell us more about it in the comments section below.

But before we go, here’s a video explaining the fix in depth:

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