Gas and Oil Home Heating Furnaces - pilot won't stay lit on furnace

We have an old furnace, but we have never had a problem with it, I think it's a century furnace, at least that's the name on the side of it, it's propane. We have been trying to light the pilot, and while holding the pilot button down there is a flame, the minute we let up on the button the flame goes out. Any ideas? Thanks for any help!! jewel

On the inside of the furnace it says, Century Engr. Corp model number EG100L, hope someone can help, can't afford to have a repairman come out and it's getting cold.

Hello jewel16

Regardless of which fuel is used, propane or natural gas, the most likely defective part would be either the thermocouple or pilot generator, depending upon which part the furnace uses.

That thermocouple or pilot generator is the part the pilot flame heats. One end of the part it will be directly in the flame of the pilot.

A thermocouple end screws directly into the body of the gas valve. A pilot generator will have two wire leads and be attached to the body of the gas valve with small screws, often on the top of the valve.

Replacing this part often solves the problem.

There are several other possibilities listed below:

The pilot flame must be all blue. No yellow.

It's also possible the magneto head contained within the body of the gas valve is defective.

A short or grounding in the low voltage wiring.

Most likely replacing the safety element {Thermocouple or Pilot Generator} resolves the problem. Try it first.

Regards & Good Luck
Forum Moderator
Tom_Bartco
Energy Conservation Consultant & Natural Gas Appliance Diagnostics Technician.

Thanks Tom for the reply, changed the thermocouple this morning. Still will not work, I have no idea what to do next. It costs so much money to have someone come to your house, and I don't have any. Is there anything else I'd be able to try myself? Thanks again for your help. jewel

Okay Tom, you mentioned that the flame should be all blue, well it isn't, it's blue on the bottom of the flame and then tipped with yellow, what does that mean? jewel

Hello jewel16

The yellow tip of the pilot flame means there is dust/lint in the pilot assembly. depending upon the type of pilot assembly your furnace has, determines whether it can be easily cleared out with a pipe cleaner or slightly compressed air.

If you look closely along the pilot assembly, somewhere behind the actual pilot flame, there will be two tiny air intake holes. This is where to insert a pipe cleaner, twist the cleaner around to dislodge and cleanout the lint/dust. Then pull the pipe cleaner out.

These same tiny holes, once located, can be cleaned out with a slight amount of canned compressed air. Or using a small diameter length of hose and blowing air throught it from one end with the other end of the hose close to those tiny holes.

Done correctly, this method clears the holes and pilot assembly and the pilot light will then be all blue and burn hot. The hot burning pilot then should encircle the tip of the thermocouple and make it very hot. [Turn cherry red}

Once the task is completed, relite the pilot and the furnace should then operate correctly.

My task is to remember to return to this forum and check for replies...:D

Regards & Good Luck
Gas Appliances Forum Moderator
Tom_Bartco
Energy Conservation Consultant & Natural Gas Appliance Diagnostics Technician