If it is unlit or isn't staying lit it could mean a problem with your gas supply, thermocouple, or ignition system. Delayed Ignition: If there is a delay between when you turn the fireplace on and the flames actually igniting, it could mean that your ignition switch is faulty or that your burner is clogged.
Push the igniter button once every second until it lights. Depending on how long it's been since the gas fireplace was last used, ignition may take multiple attempts. After the pilot lights, keep the pilot button held down about 15 to 30 seconds to warm up the thermocouple and ensure that the flame stays lit.
Dirty Burners and Obstructed Gas Lines
While moisture and rust are the most likely cause of delayed ignition, dust, dirt, grime, and even lint can accumulate and delay ignition. Delayed ignition can also be caused by a sulfur buildup caused by the process of burning natural gas.
Delayed ignition is a sign it needs to be cleaned. It's taking too long for the gas to reach the pilot flame so the gas builds up to potentially dangerous levels before it makes it to the pilot. To clean it you have to remove the logs and the stones then vacuum out the burner plate.
Gas surface burners are often slow to light or will not light at all because the burner or burners are wet or dirty, the electrode is not seated properly or the burner head and cap are not matched up properly.
Gas surface burners ignite in approximately three to four seconds. Liquid Propane (LP) models may take slightly longer to ignite the first time of the day. As long as the valve is open to the burner on a gas product, gas is delivered.
Poor ventilation can affect the flame as the vents become dirty or blocked, preventing sufficient airflow. It can disrupt the balance of oxygen and pressure needed for stable combustion, activate safety mechanisms, and lead to incomplete combustion and overheating, all of which can cause a gas fire to go out.
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.
If your pilot is lit and the fireplace isn't igniting when you push the button or flip the switch, the igniter may be dirty or defective. Clear away any dirt or debris that may be in the way between the igniter and thermocouple or thermopile.
This can be easily remedied by having your furnace inspected and cleaned by professionals before each heating season. Your furnace can also experience delayed ignition due to a sulfur build up caused by burning natural gas.
Clogged Burners or Heat Exchanger – Buildup of lint, soot, and debris can block the burners or heat exchanger passages. This prevents proper ignition and combustion. Gas Valve Defect – Defective gas valves fail to release the right amount of fuel for proper ignition.
There are certain situations which result in incomplete combustion and therefore ghosting, including: Artificial logs incorrectly placed in a gas fireplace, causing flames to impinge on a cold surface. Gas pressure that is either too low, too high, or intermittent.
Delayed Ignition: If there is a delay between when you turn the fireplace on and the flames actually igniting, it could mean that your ignition switch is faulty or that your burner is clogged. You should see and hear the gas igniting all at once (with a whoosh sound).
There are gas fireplaces that can be left burning for long periods. If the glass is properly sealed and the fireplace is fully vented this fireplace should run continuously without incident.
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.
Common causes include problems with the pilot light, thermocouple, gas supply, obstructions, ignition system, gas pressure, and weather conditions. While some issues can be resolved with basic troubleshooting, others may require professional assistance.
Using a long match or long-barreled lighter, press and hold down the gas control knob with the lit match or lighter until the pilot lights. The pilot should start immediately once the flame is close enough.
But in general, an efficiently running modern gas fire kept clear of dust and debris should hit or exceed that 10 to 15-year mark before showing signs of wear. Older or cheaper models may start to struggle after 7–8 years. Regular servicing and maintenance will be essential to maximising lifespan potential.
Fireplace thermocouple replacement costs $150 to $350 total.
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.