My furnace turns on then shuts off repeatedly

Closed Thread

  #1  
Old 12-07-08, 01:49 PM
Member
Thread Starter
Join Date: Dec 2008
Posts: 3
Received 0 Votes on 0 Posts
My furnace turns on then shuts off repeatedly

The gas turns on, the pilot lights, the flames fire up and then right before you think its going to turn on it shuts off and repeats. If i turn off from the thermostate and wait a couple mins then turn back on it works. Do you think it could be the combustion switch? Any help would be very much appreciated. Thanks
 
Sponsored Links
  #2  
Old 12-07-08, 04:00 PM
Member
Join Date: Sep 2008
Location: Long Island
Posts: 769
Received 0 Votes on 0 Posts
if you have an inducted draft motor on the furnace it might be bouncing check the tubing for cracks or loose connection into the tap to pick up the ID fan pressure.to check if it is the stat,shut the 115V safty switch on the side of the furnace,then remove the stat off the subbase.......jump R to W (thin piece of wire)and go down to the furnace...put the toggle power up and see if you get that short repeating cycle.if you DO it is something inside the furnace,if it stays solid with no restarts attempts .....it is the stat.
 
  #3  
Old 12-10-08, 03:09 PM
Member
Thread Starter
Join Date: Dec 2008
Posts: 3
Received 0 Votes on 0 Posts
Tried it sill same problem

Did just what you told me an still no results. Also the led code light stays solid so it will not tell me whats wrong. Anymore suggestions?
 
  #4  
Old 12-10-08, 04:15 PM
Banned. Rule And/Or Policy Violation
Join Date: May 2007
Location: Wisconsin
Posts: 8,629
Received 0 Votes on 0 Posts
If the flame shuts off in just a matter of a few seconds, it could mean a flame sensor simply needs cleaning.
 
  #5  
Old 12-10-08, 04:29 PM
Member
Thread Starter
Join Date: Dec 2008
Posts: 3
Received 0 Votes on 0 Posts
That is it

Your the man, took out the heat sensor, cleaned it, haven't had any problems since, thanks
 
  #6  
Old 12-10-08, 05:17 PM
Banned. Rule And/Or Policy Violation
Join Date: May 2007
Location: Wisconsin
Posts: 8,629
Received 0 Votes on 0 Posts
My good deed for the day.
 
  #7  
Old 01-20-09, 06:20 PM
Member
Join Date: Jan 2009
Location: New York
Posts: 2
Received 0 Votes on 0 Posts
Heat Sensor

Originally Posted by jjp1602 View Post
Your the man, took out the heat sensor, cleaned it, haven't had any problems since, thanks
I am having the exact same problem. Can you please tell me where I can find the heat sensor and what it might look like? This is a natural gas forced air unit.

Thanks in advance.
 
  #8  
Old 01-20-09, 06:47 PM
Banned. Rule And/Or Policy Violation
Join Date: May 2007
Location: Wisconsin
Posts: 8,629
Received 0 Votes on 0 Posts
If you have one - it will be at the end of a single thin wire that leads in towards the combustion chamber. There is no other reason for one single thin wire to run into the combustion chamber, except for one of these at it's end.

It mounts usually so you can see the metal mount portion of it, and usually only has one screw holding it in place. You undo the screw and pull it out. It will be this rod attached to the mount that you clean with steel wool, scotchbrite pad, or real fine sandpaper. (I hear people here all the time talking about never to use sand paper, yet I've used it and have never had to go back and repolish the same one -not at least for any length of time where I can remember that I did one anyway.)
 
  #9  
Old 01-20-09, 06:53 PM
SeattlePioneer's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2007
Location: Seattle, Wa
Posts: 5,503
Received 0 Votes on 0 Posts
Hey Sand---

Well, sand away and good luck to you!


But if that doesn't work I'd suggest starting a new thread to avoid the confusion caused by trying to deal with multiple problems in one thread.
 
  #10  
Old 01-21-09, 11:09 AM
Member
Join Date: Jan 2009
Location: New York
Posts: 2
Received 0 Votes on 0 Posts
Thanks ecman51,

I think I found it, but the gas valve is in it's way. It looks like a rod with a set screw on it. I tried to clean it as best as I could, but could not get to it internally. It doesnt do it all the time, but sometimes the furnace just shuts off. The vent fan will run, but the burner goes out. I also noticed that there was a lot of debris on the intake of the vent fan, so I vacuumed that out. Maybe that will help.

Thanks again!
 
  #11  
Old 04-11-13, 07:40 PM
Member
Join Date: Apr 2013
Location: Canada
Posts: 1
Received 0 Votes on 0 Posts
Thanks for the tip

Had the same issues , furnace would light then turn off......FLAME SENSOR.... Cleaned sensor with a little sand paper, furnace lite right up! You rock,Thank you
 
  #12  
Old 04-11-13, 08:50 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,003
Received 38 Votes on 33 Posts
Closing old thread .
 
Closed Thread

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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: