A gas fireplace that won't stay lit is often caused by a faulty thermocouple, an insufficient gas supply, or a blocked pilot light. Regular cleaning and inspections can often help.
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.
Other reasons your gas fireplace may keep going out include a cracked gas line, a faulty thermopile, or a blocked chimney. A cracked gas line may be caused by corrosion of the pipe material to the line. A faulty thermocouple may need to be replaced if it is not sending the correct signals to your gas valve.
Common Gas Fireplace Issues and Repair Options
Relighting is typically inexpensive unless the thermocouple requires replacement, which can range between $120 and $300.
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.
Here at Boss Plumbing, we highly recommend you not try to replace the thermocouple on your water heater yourself. Though not a highly complex water heater repair, it nevertheless does involve the use of gas. Thus, if you are unsure about what you are doing, one small mistake could lead to a disaster.
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.
Maintain oxygen flow.
If you stack wood too tight, it can snuff out the fire because the air and oxygen doesn't flow between tightly placed wood. You must stack logs somewhat loosely to allow some oxygen flow in between: One or two inches between pieces is typically a good distance.
There's really just one telltale sign of letting you know when the thermocouple isn't working, and that's when the pilot light won't stay lit. If you experience this problem, it's important to have your thermocouple assessed as soon as possible.
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.
The Fix: Pilot Light to Gas Fireplace Won't Stay Lit
This can be an indication that your fireplace thermocouple is either bad or worn out. However, if your pilot is lit but the gas fireplace isn't, then there's probably a problem with your thermopile.
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.
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.
It is highly recommended that you contact a licensed gas service provider to conduct maintenance on your fireplace at least once per year. Maintenance on gas components should not be completed by the homeowner as damage to any of the gas components could be potentially dangerous.
Fireplace thermocouple replacement costs $150 to $350 total.
A well-maintained furnace will have an efficiency rating of approaching 95%, while a gas fireplace is likely to be below that (though some are in the 90% class) and will therefore cost more per therm.
Failed Thermocouple Symptoms
You're looking for a few things. The first is signs of contamination on the tube, which can include discoloration, cracks, or pinholes. Next, check the wiring for any signs of wear or corrosion like missing insulation or bare wire.
If the pilot light keeps going out, it can cause the fireplace to shut off automatically. Common reasons for pilot light failure include drafts, debris in the assembly, or low gas pressure. First, check for any obstructions or debris around the pilot light area and clean it out.
Symptoms Pilot won't light. Pilot lights but burner won't. System lights, but goes out after a while.
The thermocouple is a safety device designed to shut off the gas valve if the pilot light goes out. Although, if your thermocouple is old, worn, damaged, wrongly positioned, or malfunctioning, it could have wrongly shut off the gas valve and prevented your pilot light from staying lit.
Blow away Debris
Use short bursts of compressed air to blow dust and debris off the first 1⁄4 inch of the thermocouple's tip. Ensure no debris falls into the pilot assembly.