Furnace shutting off

[ice_it_06]

Have a old school 30,000 btu type furnace in a perm I finally got out after two years of owning. (not enough ice to hold the 5,400 lb thing)

The furnace pilot and ignition has worked great the two years I have used it in the driveway.

The temp setting dial only works on a high out put no matter what setting you had it on, but it still worked and burned, just on high.

It would shut itself off and turn back on as needed.

Today I get the house out and it lights right up as usual, and only will burn on high out put as always.

For some odd reason it shut down various times the three hours I was in it, and it was killing the pilot light as well.

I was curious as to why it was not coming back on and after the second time it shut down I noticed the "pilot" was going out @ the same time it shut down.

Not a big deal if you are in it and hear it shut down, just relight it but I'm wondering what kind of gremlin I might have going now ?

[Whoaru99]

40,000btu???

Well, anyway, one of the first things to check is the thermocouple if it has one.

The thermocouple is that probe-looking thingy that sticks into, or very close to, the pilot light flame. There is normally a thin copper-looking tube that runs back to the gas control valve.

Don't know how to test one. I think you normally just replace it if suspect.

[Phred52]

You said that everytime the main burner went off, the pilot went too? If that's the case, I'd have to agree on the thermocouple. Generally, they are good or bad but seldom in- between. Take the old one off and take it to a Plumbing or Heating/Air Cond shop. Get 1 with as much or more length as the old one, and be sure to match the threads on the compression nut. They aren't much more than $5 or so, and then don't need to worry about that. Phred52

[ice_it_06]

Thanks for the direction guys. I look it over tomorrow and see what the deal is. I might just unhook the fuel line and stack and just take it in for repair. The thermostat or heat setting dial needs to be fixed also.

It's a 30,000 btu and 5,400 lb house. Fingers are a little beat up, so the typo errors run wild !!

[IFallsRon]

You could have a short in the wire from the thermostat to the furnace. We had a bad wire that was causing fuses in the house furnace to blow.