Any furnace peeps out there?

[bodhizafa]

Got a problem with my gas furnace, its about 20 years old. Its fired up 3 times today, for about 1 minute each time. I've replaced the thermocoupler, cleaned it out by blowing canned air through it and "wiggled" all the wires to see if something had a weak connection. Pilot flame seems fine, blew it out a few times and relit it with no problems. I also cleaned all the connections on the thermostat, it seems to work fine.

Anybody have any suggestions?:confused:

Really can't afford a new furnace right now :(

[rfranks303]

I'm not to experienced with standing pilot systems but if it was hot surface or spark ignition I would say check the flame sensor. Their may be one on your system. It would be a small rod that hangs in front of the burners, you clean them with a light abrasive just like the thermocouple.

[BC14]

Nutz on here is an HVAC guy.

[EVO8]

I agree with rfranks303, clean (steel wool) the flame sensor and see if that will solve your problem.

[bodhizafa]

I think the pilot flame ignites the burners when it starts up, no hots surface or spark .....but since I don't know what I'm talking about I may just be wrong. At least my overheating laptop is keeping me warm :)

[rfranks303]

Yes the pilot does light the burners. The other two do not apply but that's where my experience lies. On those types of systems there is a flame rod that hangs in front of the burners and that's what you clean. On a standing pilot there may be one. Something has to prove ignition. It may use the thermocouple to do this but we assume the thermocouple is good because the pilot is present. If it does not have a flame rod or other kind of sensor near the burners I would change the thermocouple anyway because its a 10 dollar part that COULD be causing issues. If you need to ask me any questions you can shoot me a pm and it will go to my phone.

[Wrider]

Yup, same thing ours did last year. Clean off the flame sensor and you should be golden.

[bodhizafa]

Thermocoupler was changed this morning. What does the flame sensor look like?

Wish there was a damn manual for this thing online somewhere.

[bodhizafa]

Anybody now how to check the gas valve? Wondering if that is bad.

[mastap07]

it sounds like the flame sensor to me too. it will look like a silver rod 2 to 4 inches long, steel wool is best to clean it as sandpaper and or emery cloth will leave a residue on the sensor shortening its life. the flame sensor will hang down in front of one of the gas ports (where the gas shoots out to be ignited). that should fix your problem. i dont believe your gas valve has any issues as they are less prone to fail but you have gotten good life out of your furnace. the thrermocouple will operate the valve inside the gas valve to open and close. you can also shoot me a pm if you have any questions.

[Foolds]

could be the Evac Motor for getting ride of the Carbon Monaizide(sp?)

When it starts up and starts to run.. do you see a flame? should be lit across all of the burners. 20 year old furnace might has a solid ignighter on it(think kinda like a toaster, rather then a pilot light.

[NUTZ]

On a standing pilot your not going to have a flame sensor or a induce draft motor on the flue.

Does the fan kick in at all?

And dear god man, if you don't have carbon monoxide detectors in or near your bedrooms, get them NOW! On a furnace that old I can almost guarantee the heat exchanger is cracked...

[Canuck]

And dear god man, if you don't have carbon monoxide detectors in or near your bedrooms, get them NOW! On a furnace that old I can almost guarantee the heat exchanger is cracked...

:rolleyes:
The CO detector is a good idea and the furnace should be replaced fairly soon due to its inefficiency. But to state that it most likely has a cracked heat exchanger simply due to age, is irresponsible.

[bodhizafa]

Needed new gas valve. Had it replaced ($$$ :( ) works great now. Hopefully it will last another year or so. Then I'll get a new one. Thanks for the help.