Furnace Pilot Light Keeps Going Out Thermocouple

The pilot orifice may be full of dirt.

Furnace pilot light keeps going out thermocouple.

The biggest reason a coleman furnace pilot light keeps going out is the thermocouple is placed too far from the pilot light. If you can t get the flame to light at all and you re sure the gas is on there s probably an obstruction in the pilot tube. Thermocouples work by producing a small amount of voltage when it is heated. The thermocouple is a rod that comes into physical contact with the flame in your system.

The pilot light must heat the thermocouple so the thermocouple can keep sending an electrical charge back to the furnace which keeps the gas valve from shutting closed. Either the thermocouple is going bad or it is dirty and needs to be cleaned. A weaker flame won t envelop the thermocouple properly. Cleaning out the pilot orifice means disassembling the pilot and clearing out the debris using a needle or compressed air.

The thermocouple is a sensor inside a steel sleeve that sits in front of the pilot light. Which means the thermocouple will shut off the gas flow to your furnace as a safety measure. You see the pilot light orifice controls the flow of gas to your pilot light. This component will deactivates the gas when the pilot light goes out.

A bad thermocouple itself can prevent a gas furnace or boiler from working if you can light the flame at the pilot manually but then the flame goes out when you release the manual gas feed valve the thermocouple is probably bad. But if the orifice is dirty or restricted the pilot light won t light properly. What s the difference between a thermopile and a thermocouple. This is the pilot flame that provides the heat.

If your furnace pilot light keeps going out it s likely you have a broken thermocouple in your gas furnace. The pilot light is supposed to be a strong blue cone not a weak yellow flame. The pilot light needs a strong flow of gas to make a strong steady blue flame that the thermocouple can sense.