Gas and Oil Home Heating Furnaces - Furnace wont ignite itermittent problen

I have A lennox G20 series gas furnace with electronic pilot ignition. The problem is that the when the thermostats send the signal to ignite some times the pilot does not ignite. If I switch of the thermostat and start again it ignites (I might have to do this a couple of times). In addition some times when the furnace is running it will stop on its own before it reaches the desired temperature. I am new at all this and am looking for some advice …

Does it electronicly light a flame for the pilot or does it just glow red and light the burners?

The pilot intermitantly not working and the gas shutting down could be a gas valve or circuit board problem or could be dropping out from the air proover.

You would need a multi-meter to check these things.

Thanks for the reply

I think it lights a flame as i can hear the starter going tick tick for some time before it gives up ....


The thing that is totally confusing is that it does it some times and is ok other itmes...

Going thru the same problem here,clicking nose would not fire at all just changed the ignitor and took care my problem. Might not be the problem you are having but, maybe you can check it out. Good luck

If it keeps on ticking and no pilot a few things can be the problem.

-gas valve on all the way?
-Pilot valve getting power?
-Pilot assembly clean?

Most of the time I can clean the pilot orfice and get the pilot to burn.

This takes a tool called a broche. It looks like a sewing machine needle and is sized to give the proper amount of gas to the pilot burner.