Fan won't turn on manually


  #1  
Old 01-02-10, 07:06 AM
R
Member
Thread Starter
Join Date: Dec 2006
Location: Ohio
Posts: 246
Received 0 Votes on 0 Posts
Fan won't turn on manually

The fan on my system won't run when I switch the fan switch from "auto" to "on." Other than that, the system works normally.

The switch worked fine until recently. What can I do to troubleshoot this?
 
  #2  
Old 01-02-10, 10:56 AM
SeattlePioneer's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2007
Location: Seattle, Wa
Posts: 5,499
Received 0 Votes on 0 Posts
What's the make and model of the furnace, which can be obtained from the rating plate in the furnace burner compartment?
 
  #3  
Old 01-02-10, 12:14 PM
R
Member
Thread Starter
Join Date: Dec 2006
Location: Ohio
Posts: 246
Received 0 Votes on 0 Posts
Coleman direct vent forced air furnace - model 7956B856 - (mobile home)
 
  #4  
Old 01-02-10, 12:50 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,381
Received 35 Votes on 33 Posts
Fan ON

I wouldn't worry with it but if you really want it to work we can do some troubleshooting. Do you have A/C & does the furnace fan usually run when the A/C is on?
 
  #5  
Old 01-02-10, 01:26 PM
R
Member
Thread Starter
Join Date: Dec 2006
Location: Ohio
Posts: 246
Received 0 Votes on 0 Posts
I do want to go to the trouble to fix it as I use it often.

Yes, I have A/C and the fan does run when the A/C is on.
 
  #6  
Old 01-02-10, 01:38 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,381
Received 35 Votes on 33 Posts
Fan Problem

Remove the thermostat & temporarily install a jumper between terminals R & G (a paper clip will work). If the fan comes on, the thermostat switch is bad. If no fan, remove the jumper, turn off the a/c AT THE BREAKER, set the stat for cool & well below room temp. If still no fan, it's likely a relay in the furnace or the fan motor's cooling speed is shot.
 
  #7  
Old 01-02-10, 02:48 PM
R
Member
Thread Starter
Join Date: Dec 2006
Location: Ohio
Posts: 246
Received 0 Votes on 0 Posts
I shorted R and G and the burner started. No fan, just the burner as if I had raised the setpoint.
 
  #8  
Old 01-02-10, 03:02 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,381
Received 35 Votes on 33 Posts
Something's wrong

No way should jumpering R/G bring on the burner. Either try the A/C test or repeat the R/G jumper test at the furnace terminal strip. If testing at the furnace, leave the stat off the wall.
 
 

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