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 not allow the gas valve to open if the pilot light isn’t lit.

How do you fix a gas fire that keeps going out?

Easy DIY Fix: Gas Fireplace Won’t Stay Lit

  1. Before You Begin: Is Your Pilot Light Lit Inside Fireplace?
  2. The Fix: Pilot Light to Gas Fireplace Won’t Stay Lit.
  3. Check Your Thermopile Output with the TH/TP Contacts.
  4. Don’t Replace Your Thermopile or Thermocouple Right Away.
  5. Cleaning the Thermopile.
  6. Re-test the Cleaned Thermopile.

How do I know if my thermocouple is bad on my gas fireplace?

Quote from the video:
Quote from Youtube video: You should replace the thermocouple. So to recap the readings to look for are 8 to 30 millivolts. And if the readings are less than 7million. You should replace the thermocouple.

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

between $150 and $250

When replacing a thermocouple or thermopile with the help of a professional, you can expect to pay between $150 and $250.

How do you bypass a thermocouple?

Quote from the video:
Quote from Youtube video: This is the thermocouple. Okay that's the thermocouple here's a main igniter wire. And here is the tube that gives you propane. So you follow this wire down.