Induced draft motor cycleson a nd off


  #1  
Old 02-27-13, 11:46 AM
J
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Induced draft motor cycles on and off

My Goodman model GMP 125-4 gas furnace has an induced draft motor that has recently started short cycleing, intermitantly. Sometimes it will run for a few seconds and shut off, sometimes for only a second. Sometimes it will funtion as it always has, start and run for 20-30 seconds, then the burner will come on and run a normal cycle. When the thermostat calls for heat is the only time it comes on, but sometimes it will shut off without anything else happening. Sometimes it turns on and off a number of times before it will run a normal burn cycle. Whenever 110 volts is applied to the motor it runs, so I know something else is opening, causeing it to shut off.
 

Last edited by joe9212; 02-27-13 at 12:06 PM.
  #2  
Old 02-27-13, 06:36 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,605
Received 3,884 Upvotes on 3,481 Posts
Welcome to the forums.

There is a control board in your furnace that pretty much runs the show. Your draft inducer (power venter) is connected to common neutral and IND terminal. There would be 120 vac on those terminals when the inducer should be running.

There is a PVR (power vent relay) on that board. When thermostat calls for heat that relay would engage and start the inducer blower. If the thermostat had an issue..... you would hear that relay chattering in time with the inducer starting and stopping.

Based on not hearing that relay chattering ...... the relay contacts are burned/intermittent and the control board needs to be replaced.

In the link your schematic is on page 67 of the PDF.

http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf
 
  #3  
Old 03-03-13, 08:26 AM
J
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks

That seems logical. I thought it had something to do with the control board. After reading your post I waited for the problem to surface again and when it did I explored further. I found that by tapping on a black plastic cube attached to the control board I could effect the power venter turning on and off. Thanks for the advice.
 
  #4  
Old 03-03-13, 09:02 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,605
Received 3,884 Upvotes on 3,481 Posts
That black plastic cube would most likely be a relay.
It's good you were able to reproduce the problem. Intermittents can be pretty difficult to isolate.
 
  #5  
Old 03-03-13, 09:54 AM
J
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks again

Guess I'll be trying to get a control board...that couldn't cost to much, ha ha
 
  #6  
Old 03-08-13, 05:30 AM
J
Member
Thread Starter
Join Date: Feb 2013
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks

$110 for new board. Fairly easy to install. Been working fine for a few days now.
 
 

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