Gas furnace - pilot light issue

[Nate_K1500]

Originally Posted by trophybook

Hi temp limit switch may be pooched

This is exactly what is happening ^^
its not sending the signal to your blower to tell it to turn on and start pushing the hot air into the house. So now it keeps getting hotter and hotter till the high high level sensor tells to shut down before it melts your house down.
Replace the temp switch ($6) and your back in business!!

[dewalt18]

A furnace with a standing pilot will likely have a Honeywell combination switch, which is basically a temperature controlled device that tells the blowers when to turn off, turn on, and controls the high limit safeguard.

If you can buy one of these for $6, buy a bunch because they sell wholesale for about ten times that price. . .

[burnme]

Originally Posted by dewalt18

After reading the original post, I'm thinking maybe you should take a look at your filter. Not all, but some furnaces will have an interlock between the high limit and the gas valve. If your filter is clogged up, it will run until the furnace over heats, with you thinking it was a full cycle, but will go into safe mode, disabling heating function. Just a thought. Would have to see it run in person to do a proper diagnoses.

This is exactly what happened to my daughters place last year. Wont even say how bad the filter was.

[normstad]

Originally Posted by TylerThomson

K its not that then. A yellow flame indicates poor air flow or soot build up. When you installed the new thermocouple did anything get bent? If the flame isn't on the end of the thermocouple it may not be getting hot enough.

Just a follow-up and thanks to all that made suggestions.

Furnace seems to be working fine. I adjusted the thermocouple downwards so the pilot light constantly keeps the heating the tip. I had assumed that as long as the light was on the bulk of the body, that would be fine.

Again, thanks, and sorry for the delay in giving it.