Gas furnace heat does not work


Old 11-14-05, 09:55 PM
Visiting Guest
Posts: n/a
Question Gas furnace heat does not work

I have a gas furnace. it is roughly 5 years old. i don't know the brand. When i turn on the heat, i can hear the furnace turn on, but it does not get to the point where the fan turns on. I have read through some other postings and i think that my pilot does not cut on or the main heating elements do not cut on. what is the best way to diagnose the furnace for this problem. Also, how do i remove the door in order to see what might be happening inside the furnace? unfortunately the furnace is in a crawl space under my home so it is quite difficult to get to
I appreciate all the help ahead of time.
Sponsored Links
Old 11-16-05, 05:44 PM
Bonehead's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2005
Posts: 202
Received 0 Votes on 0 Posts
What kind of crawl space? A damp and dank one? If you have such a furnace in such a place, contacts can tarnish. You really need to go down there periodically to check on that furnace, open up both covers (the big one on top, and the small one on the bottom. Slide them up, then out), and observe the terminals and also see if unwanted bugs/spiderwebs, etc., are in there. Also, you need to check the furnace filter anyway. You *have* checked and or replaced the furnace filter in some recent point in time, haven't you? You also want to make sure creatures are not in there/ate holes through the a mouse or bat. With the furnace off, spin the blower wheel in the bottom compartment, by hand, to see if it turns freely. It should stay spinning even after you stop spinning it. See if your blower motor has places to oil it. (Often times, right on the blower it weill say if it requires oiling or not) Also, the ventor mortor may or may not need oiling.

After you have done this preliminary stuff, flip on the furnace switch with the thermostat turned up. Turn it up enough for the test so that you don't get fooled by having it shut off on you. But remember to trun it back down to room temperature after you are through testing.

Then run the furnace.

Then get back with us and tell us what happens.

This is what SHOULD happen, in this order. The first thing is that the exhaust gas blower (the ventor) should kick on. Then, after a short while, then you should see either a bright glow from a hot surface ignitor or the sparking from a spark-type ignition system (usually a thicker spark plug looking wire leading into the burner area, and may be orange). Then, within seconds, you should be able to hear a little click come from the main gas valve, and either a pilot will light, if it has one, or, the burners will ignite.

Get back with us and then explain at what point things don't happen...after you have done those things in my opening paragraph.

You have to be down there to observe if you see any glow, spark or flame whatsoever.

Oh. You have to put back on the bottom smaller door , or else the furnace won't even start up. But leave the big one off. That one is where the burner can be seen. Also, let us know if you have 1 or 2 pvc pipes coming out of the furnace.

Last edited by Bonehead; 11-16-05 at 06:11 PM.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes
Ask a Question
Question Title:
Your question will be posted in: