BACKDEC 8, 2025
There’s nothing quite like the cozy ambiance of a flickering fire on a cold night. You grab a blanket, settle into your favorite chair, and reach for the switch to turn on your gas fireplace… but nothing happens. The warmth and comfort you were anticipating are replaced by frustration and a sudden chill.
Looking for more guidance? Take a look at our Repairs overview.
If your gas fireplace won't light, don't worry. You're not alone, and the solution is often simpler than you think. Many common issues can be fixed without calling a professional.
Here at Casa, we want to empower you to handle these problems with confidence. Think of us as your friendly expert on the other end of the line, ready to walk you through the process step-by-step. Let's get that fire roaring again.
Before we touch a single dial or switch, we need to talk about safety. We're dealing with natural gas, and it’s crucial to be cautious.
Your first action should always be a quick gas leak check. Natural gas is odorless, so utility companies add a substance called mercaptan, which gives it a distinct smell, often described as rotten eggs or sulfur.
Here’s what to do:
If you smell gas or hear a hissing sound, DO NOT proceed. Do not turn any lights on or off, do not use your phone, and do not try to find the leak yourself. Immediately leave the house, and from a safe distance, call your gas company's emergency line.
If you don't smell or hear anything unusual, it's safe to move on to the next steps.
It might sound obvious, but one of the most common reasons a gas fireplace won't light is that the gas supply is turned off. This can happen accidentally during cleaning or if it was shut off at the end of the last cold season.
Locate the gas shut-off valve, which is usually a small handle near the fireplace unit. For the gas to be on, the handle should be parallel to the gas pipe. If the handle is perpendicular to the pipe, it's closed.
Gently turn the handle so it's parallel with the pipe. Wait about a minute for the gas pressure to stabilize, and then try lighting your fireplace again. If it ignites, you’ve found your simple fix! If not, let's dig a little deeper.
Gas fireplaces typically have one of two types of ignition systems, and the troubleshooting steps are different for each.
Knowing which system you have is key. Let’s tackle the troubleshooting for each one.
If you have a standing pilot system, the pilot light itself is the most likely culprit.
Look closely through the glass front of your fireplace. Do you see a small, steady blue flame? If not, the pilot light is out, and the main burner has no flame to ignite from. Relighting it is your next move.
How to Light the Pilot:
If the pilot light goes out as soon as you release the knob, it's usually a sign of one of two things: a dirty pilot assembly or a faulty thermocouple.
1. Clean the Pilot Assembly: Over time, soot and debris can clog the small opening where the pilot flame comes out. This weakens the flame, preventing it from properly heating the thermocouple.
Once clean, try the pilot-lighting procedure again.
2. Check the Thermocouple: The thermocouple is a safety device that shuts off the gas if the pilot light goes out. If it's failing, it won't signal the gas valve to stay open, even when the pilot is lit.
You can check if it's positioned correctly—the tip should be fully engulfed in the pilot flame. If it’s loose, you may be able to tighten it. With the gas off, find where the thermocouple connects to the gas valve and ensure the nut is snug (hand-tight plus a quarter-turn with a wrench). If cleaning and tightening don't work, the thermocouple may need to be replaced, which is a fairly inexpensive part.
If you have a healthy pilot flame but the main fireplace won't turn on, the issue is likely with the switch or remote control.
Troubleshooting an electronic ignition system is a bit different, as it's more about power and sensors than a constant flame.
No power means no spark.
Just like any electronic device, sometimes the control module needs a simple reset.
Some modules also have error codes indicated by a blinking LED light. Consult your owner's manual to decipher what these codes mean.
Modern direct-vent fireplaces have sensors that prevent ignition if the exterior vent is blocked. This is a safety feature to prevent carbon monoxide from entering your home.
Go outside and locate the vent termination cap. Look inside for any obstructions like leaves, bird nests, or snow. Carefully clear away any debris you find.
While many of these fixes are straightforward, gas is not something to experiment with. If you've tried these steps and the fireplace still won't light, or if you're ever uncomfortable performing any of these checks, it's time to call a certified gas-fireplace technician.
Hiring a professional for a service call typically costs between $100 and $300, depending on your location and the complexity of the issue. This is a small price to pay for safety and peace of mind. Issues like a faulty gas valve or a complex electrical problem are best left to the experts.
Fixing a gas fireplace that won't light can be a satisfying DIY project. By following these steps safely and methodically, you can often solve the problem yourself and get back to enjoying that warm, cozy glow.
For more helpful guides on home maintenance and for those moments when you need to connect with a trusted professional, download the Casa app. Casa is designed to be your go-to resource for everything from simple fixes to major repairs, putting expert advice and reliable help right at your fingertips. Stay warm
