When a fire pit keeps going out, the cause is almost always the flame-sensing thermocouple. If the flame goes out immediately after you light your fire pit, this is an indication that the thermocouple isn’t sensing the flame and it’s turning off your gas supply.
It’s a common problem, but our easy-to-follow steps below will help you diagnose and fix it.
What is a Thermocouple?
A thermocouple is a safety feature of gas fire pits. It automatically turns off the gas supply if it doesn’t sense a flame. This ensures that you won’t have gas flowing from your fire pit unchecked and filling the immediate area with combustible gas.
When the thermocouple senses the heat from the flame, it generates a small amount of voltage, which holds a solenoid (magnetized valve) open allowing gas to flow.
To learn more about gas thermocouples and how they work visit our article, “Thermocouples: Everything You Need to Know (and Then Some!).”
Troubleshooting
Step 1: Clear all Fire Glass from Around the Thermocouple
The thermocouple is located inside a metal box with holes on all sides. The holes provide ventilation for the flame, which is directed at the thermocouple. Often, the placement of fire pit glass around the cage, or a small piece of fire glass that works its way inside the cage, is the source of the problem.
To test for this, clear all fire glass away from the cage making sure all sides and the top of the cage are completely clear. You should have at least 2 inches of clearance on all sides. Also, check that there is no fire glass inside the cage.
If this fixed your problem, start moving the fire glass back around the cage. Do this slowly and in small increments to ensure you don’t restrict the airflow too much. If the flame goes out, move the glass back to where it was when it was still lit. Never cover the top of the cage.
Step 2: Inspect the Thermocouple
If the previous step didn’t fix your problem, we’ll have to take a closer look inside the gas fire pit thermocouple.
It’s best to do this out of direct sunlight. In fact, early evening is the best time to try this. You’ll have enough light to see what you’re doing, but less sunlight will make it easier to spot a small flame.
Light the fire pit and carefully look inside the cage. Can you see a flame touching the flame-sensing thermocouple?
If you see a flame and it’s touching the thermocouple, make sure you’re holding the control knob in long enough (15 to 20 seconds), so that the thermocouple can reach its operating temperature.
If the flame still goes out, it’s likely you have a bad thermocouple. In this case, you’ll need to replace it.
Note: Replacing a thermocouple involves the use of gas. It’s always best to have the repair made by a professional gas plumbing company.
If you don’t see a flame touching the thermocouple, you’ll need to figure out why. Perhaps, the flame is off center and not aligning with your thermocouple, etc.
If there’s no flame at all, it could be a problem with the gas supply feeding the flame.
Here to Help
If you still have questions about how to troubleshoot this problem, don’t hesitate to give our
Celestial Glass Technical Team a call or send an email. We’re happy to help walk you through this process.