How do you fix a low flame on a gas fireplace?

Author: Marlee Kihn  |  Last update: Thursday, June 18, 2026

You can use canned air to blow through the burners and remove any debris from the orifices. Removing such debris is vital because it could inhibit or block the flames. This is one of the causes of low flames in your fireplace. It is also helpful to look for any blockages in the burner orifices.

Why is my gas fireplace flame so low?

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 does my fireplace have a small flame?

Typically low flame height is caused by one of three things. Either you have low gas pressure at the fireplace or you need to restrict the venting to slow down the draft. 1) It is common to think that the gas pressure is fine when this only one appliance on the line or the meter is turned all the way up.

Why is the flame on my gas burner low?

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.

What causes a weak flame on a gas furnace?

Spider webs, dust, or dirt buildup can block the pathway of the pilot light, leading to a weak flame. These obstructions prevent the proper flow of gas and air needed for a strong and steady pilot flame. It's essential to regularly inspect and clean the area around the pilot light to ensure unobstructed operation.

Spider web clogging gas line of Heatilator fireplace

Why does my gas fireplace keep losing flame?

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.

How should a gas fireplace flame look?

you always want to see a blue color flame. A gas flame appearing yellow or orange in color or behaving with pops of yellow or orange indicates an improper ratio of oxygen for combustion. Often this improper combustion is temporary and could be caused by dust particles or a dirty burner that needs cleaning.

Why is my gas fire not burning properly?

A variety of burner problems can develop in a gas fireplace, leading to issues like a flickering flame or flame that gets too tall. Insufficient voltage, a failing thermocouple or malfunctioning thermostat are common causes of flickering burners. The burner or pilot may be dirty.

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 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.

How much does it cost to replace a thermocouple on a gas fireplace?

Common Gas Fireplace Issues and Repair Options

Relighting is typically inexpensive unless the thermocouple requires replacement, which can range between $120 and $300.

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.

Why is my gas fireplace flame not high?

A clogged or faulty burner can cause performance issues resulting in a low gas flame. In addition, carbon build-up, gas residue, and debris can inhibit the burner's ability to function correctly, leading to premature failure. If cleaning the burner doesn't solve the problem, it may need to be replaced.

How long does a thermocouple last on a gas fireplace?

Thermocouples can last up to 10 years if properly installed and maintained, while furnaces can last 15-20 years, although either may wear out sooner in multifamily units.

Is it normal for gas fireplace to have small flame?

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.”

Why is the flame on my gas heater too low?

One possibility is the clogging of burner ports. The burner ports are the little openings in the stovetop through which the gas flows. If they become blocked with food or particles, the gas will not be able to flow correctly, and the flame will be low. A failing gas valve is another possibility.

Why does my gas flame keep going out?

Low gas pressure or a faulty gas valve can interrupt the gas supply, causing the fire to burn out. If you can smell gas near the fire, hear hissing sounds, or the gas leak detectors activate, you must contact a professional right away to check for safety.

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