Gas Fireplace Keeps Going Out? (Here's How to Fix It)

Ossiana Tepfenhart
by Ossiana Tepfenhart

Ah, fireplaces. Since the chimney was invented, having a fireplace was one of the most important ways people got heat in their homes and cooked their foods. Even today, we use them to cozy up on colder days. Nowadays, most people have gas fireplaces instead of wood. Sometimes, that leads to issues that can make them frustrating–like going out when you want it to stay lit.

Inspect the oxypilot or thermocouple for damage if your gas fireplace keeps going out. Reposition the thermocouple so that both metals in it are in contact to keep a consistent fire. Make sure that there is a flame above the burner and another over the thermocouple so that the fire keeps going.

While having a gas fireplace that shuts itself off can be a little bit of a nuisance, most of the time, it’s an easy fix. This guide will tell you how to make sure your gas fireplace stays lit and when it may be better to call a professional to fix it.

Do You Need Chimney or Fireplace Cleaning or Inspection?

Get free, zero-commitment quotes from pro contractors near you.

Why Does My Gas Fireplace Keep Going Out?

If you’re struggling with keeping your fireplace lit after 20 minutes to an hour, chances are that you have a sensor or a valve that’s going bad. In most cases, this means that your thermopile (the sensor/valve that keeps an eye on your fireplace temperature) or your oxypilot (the sensor that keeps an eye on your fireplace’s oxygen levels) is in need of cleaning.

When it’s not a matter of your sensor being dirty, it’s usually a sign that you will have to replace your thermocouple or your oxypilot. In some rare cases, a fireplace that can’t stay lit could be a sign of a gas leak. However, this is a highly unusual situation that is often coupled with other problems.

How the Pilot Works in Your Gas Fire

Starting up a gas fireplace begins with shifting the pilot light to the “on” position. In some cases, you may need to hold it longer to allow the fire to “kick on.” When you first attempt to start up the fire, you should always keep an eye on the pilot light. Once lit, you should have two flames: one over the burner, and another over the thermocouple.

If the pilot is dirty and needs to be cleaned, you will have a very weak flame. This will case the flame to lift away from the thermocouple, the temperature to drop, and the gas valve to shut off.

In addition to the condition of the flame, the color of the fire emitted by the pilot makes a difference. It should be dark blue in the outer flame, and sky blue in the center. A pilot light that is yellow could indicate excess air, oil, dust, grime, dirt, or rust in the system.

How the Thermocouple Works

The thermocouple must stay in constant contact with the flame of the pilot. It is essentially a sensor that measures temperature and is made up of two different types of metals, joined on one end.

When the connection of these two metals is heated or cooled, a voltage is created that can be linked back to the temperature. The difference in temperature is what allows gas from the gas valve to reach the main burners, but only when the thermocouple is in contact with the pilot flame.

How the Oxypilot Works

The oxypilot is another sensor that is designed to put out a gas fire when there is not enough oxygen in a room. It is a safety mechanism that protects you and your family from carbon monoxide poisoning.

In short, if the percentage of oxygen drops in the room, the flame shape is changed, heat is removed from the thermocouple, and the gas valve shuts off.

How To Troubleshoot (And Fix) Your Gas Fireplace

A gas fireplace that keeps shutting off is annoying, but it’s not the end of the world. The gas fireplace issues that you’re dealing with are usually fairly fixable. Here’s how to make your gas fireplace work again:

  • Shut off the gas. You should never try to fix a gas fireplace when gas is still running to your unit.
  • First things first, clean your thermocouple. Look for a stick that has a thermometer-like appearance. That’s you’re thermocouple. Check to make sure that it’s in the direction of your pilot. Then, use a scrap of fine-grit sandpaper to clean off the thermocouple’s tip. This will get rid of any soot and oxidation.
  • Test your fireplace. In most cases, the thermopile’s touch-up will be enough to get your fireplace working well. So, turn the gas on and give it a light. If it still shuts off, it’s time to shut the gas off and move to your next step.
  • Next, check your oxypilot. You will need to unscrew this device and remove it. Use a straw to blow through each of the oxypilot’s holes. This should get rid of the soot and dust that could have caused an airflow misread. Once you’ve cleaned your oxypilot, reinstall it.
  • Test your fireplace again. If it works, then you’re good to go and no other troubleshooting needs to be done. Otherwise, it’s time to look at the other item that could have gone bad.
  • Clean out the pilot’s gas entry. Sometimes, dust can throw off the whole thing. Blowing away any dust or using a cloth to clear it up can help.
  • If your gas fireplace still keeps shutting off, it may be time to replace your sensor and your oxypilot. This is when it’s usually best to hire a professional since this will involve parts replacement.

When Should You Call A Professional?

If you are working with a gas fireplace and can’t seem to fix the problem through regular cleaning or troubleshooting, you should call a professional. Due to the risk of fire hazards and the difficulty that can arise when it comes to finding the right parts, most experts agree that it’s better to call a licensed and certified gas technician.

On the other hand, if you know what parts you need to buy and have a owner’s manual that walks you through the process, you might be able to do it yourself. If you do choose to DIY it, make sure to follow the steps to the letter and keep an eye on other parts while you do it. You don’t want to cause additional problems.

How Much Does Getting A Gas Fireplace Repaired Cost?

The prices can vary greatly depending on the type of fireplace you have as well as the issue that is causing your fireplace to stop lighting. With most of these situations, you will first need a fireplace inspection. An inspection alone can cost between $60 and $130. Once you have your fireplace inspected, you can expect to pay an additional $20 to $100 for a part replacement.

What Should I Do If My Fireplace Won’t Stay Lit And I Smell Gas In My House?

Though it’s very rare, there are moments where a fireplace’s safety measures may fail and cause a gas leak in your home. Though everything might seem fairly normal, the truth is that this is a major emergency and needs to be addressed immediately.

Should this occur, stop what you’re doing. Do not light any matches or candles nearby. Get everyone out of the house (pets included) and call 911 once you’re outside. Make sure to report it as a gas leak, and explain why you believe it may be coming from your fireplace. A gas leak is a very serious threat to your home and can quickly turn into a raging fire.

Do You Need Chimney or Fireplace Cleaning or Inspection?

Get free, zero-commitment quotes from pro contractors near you.

Related Questions

Can you fix a thermocouple?

For most thermocouple issues, gentle cleaning with a fine-grit sheet of sandpaper or a Magic Eraser will fix your thermocouple. In most cases, a thermocouple that has gone bad won’t be able to be fixed. Thankfully, it’s fairly easy to replace a thermocouple and it’s not that expensive to do.

Can I bypass a thermocouple?

Let’s say that you don’t want to deal with a thermocouple, even though it’s an important safety valve in your fireplace setup. It happens. Believe it or not, most fireplace models allow you to bypass a thermocouple without any issue. Though it will add some risk, not using a thermocouple will only raise the risk to the same level as a gas grill.

Do you need to have a chimney for a gas fireplace?

Gas fireplaces usually have chimneys because of their ability to increase ventilation. However, it is possible to find a fireplace that doesn’t have a chimney. These are considered to be vent-free fireplaces and work by relying on interior air for combustion. Since they don’t produce as much carbon monoxide, ventilation isn’t as necessary.

Can you mount a TV over a gas fireplace?

Though gas fireplaces can exude smoke and heat, mounting a TV over one is actually fairly safe. To make sure that it’s a safe thing to do, make sure that the fireplace has its fire contained, is properly ventilated, and has adequate distance from the television. When you’re mounting the TV, make sure to use sturdy equipment.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

More by Ossiana Tepfenhart