If the pilot light on your gas fireplace won't stay lit, a very likely culprit is a component called a thermocouple. A thermocouple is a safety device and is a component of the ignition system. Its purpose is to prevent the gas valve from opening if the pilot light isn't lit.
So you've checked your pilot light and even reset it, but still, it wont 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.
There are many possible reasons why the burner will not stay lit - the gas jet may be blocked, the valve may be set too low, the air flow may be restricted, there may be an issue with the pilot light, and so on.
Key Takeaways: Thermocouple issues, pilot light problems, blocked venting systems, safety features, and gas supply issues are common reasons why gas fireplaces shut off. Regular maintenance, cleaning, and professional servicing are essential to prevent unexpected shut-offs.
IF the pilot goes out when you release the knob it is either a pilot flame issue, thermocouple issue or the holding coil in the gas valve has failed. First thing to do is to disconnect the thermocouple connection from the gas valve body and clean the contacts, then re-install the thermocouple connection.
Dirty or Damaged Thermocouple Explains Why Pilot Light Keep Going Out. A faulty, misaligned, dirty, or damaged thermocouple is often the culprit behind your pilot light going out. The thermocouple is an automatic safety shutoff device that prevents the gas valve from opening if the pilot light is out.
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.
Some of the possible serious reasons for pilot lights to go out include loose or broken gas valves, thermocouples or heat exchangers, faulty venting, low gas pressure, or high winds. If you believe there is a serious problem, don't hesitate to contact a professional.
Fireplace thermocouple replacement costs $150 to $350 total.
Gas Fireplace Igniter Isn't Sparking
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.
The most common cause of this is dirty or blocked burners, which is the part that you can easily take off to clean.
Keep your thumb on the gas.
You must keep the gas flowing to the pilot until the thermocouple is warmed up. This might take as little as 10 seconds, but I'd give it a full minute. Once you take your thumb off the valve, it should pop back out and the pilot should remain lit.
When your gas fireplace won't stay lit, it's often due to pilot light, thermocouple, or gas supply issues. Regular maintenance, cleaning debris, and inspecting components can resolve most problems. However, safety concerns and complex repairs should be handled by a professional.
Relighting is typically inexpensive unless the thermocouple requires replacement, which can range between $120 and $300. Ignition Problems: Often caused by faulty igniters or control valves, ignition issues may cost from $150 to $600, depending on the components needing replacement.
Insufficient airflow or insufficient gas pressure. A defective, malfunctioning ignition board, flame sensor, light switch, thermostat, thermocouple, fan limiter, or draft inducer fan. The drainage line is blocked, resulting in a full condensate pan. Temperatures are so low that the furnace cannot stay lit.
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.
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.
Symptoms Pilot won't light. Pilot lights but burner won't. System lights, but goes out after a while.
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.
Your Gas Valve Needs Attention
The gas valve on your furnace delivers the gas your pilot light needs to remain lit. If the valve is turned ON, but your pilot light won't stay lit, the problem might be a broken gas valve. The solution most likely will be to replace the valve.
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.
Clean the Thermocouple: Use a brush or compressed air to remove any debris or dust on the thermocouple. A soft-bristled brush works well for this. Handle with Care: Be gentle during cleaning to avoid damage.