nonstop air, no heat: American Standard Freedom 90


  #1  
Old 12-29-12, 11:50 PM
D
Member
Thread Starter
Join Date: Dec 2012
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
Unhappy nonstop air, no heat: American Standard Freedom 90

Okay, so I have an American Standard Freedom 90 Single Stage furnace, and the blower just runs all the time from the moment it is turned on. What's worse is that the air never heats up! I've already replaced the Hot Surface Igniter (it was bad), but it never ignites or even glows.

I tried different wires on the thermostat, and thermostat is set to OFF with Fan on AUTO. Fan never turns off though, even if I set it to ON then AUTO.

I tested the High Limit Switch (back wall) for continuity and got it, and I tested and got continuity on the rollout Switch underneath the burner area (even reset it with the red button), and heat never comes on nor does fan ever stop.

Any suggestions?

EDIT: Oh, and no flashing light codes display on the board. There is a red LED there, but it doesn't light up or blink.
 
  #2  
Old 12-30-12, 01:31 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,055
Received 2,951 Votes on 2,663 Posts
For those of us who don't recognize that exact unit......we need a model number.

With some furnaces.....the blower will stay on if there is a safety sensor issue.
 
  #3  
Old 12-30-12, 08:56 AM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 4 Votes on 4 Posts
First thing to check due to the led diagnostic light not being lit up at all is low voltage power and possibly a blown low voltage fuse on the control board.
 
  #4  
Old 12-30-12, 10:24 AM
D
Member
Thread Starter
Join Date: Dec 2012
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
I think that this is the model:
aux100c948d3

Anyways, it's the only Model number listed on both the inside and outside of the furnace, unless I'm not looking in the right place.

And the fuse on the Control Board is okay. Forgot to mention I checked that already.
 

Last edited by hvactechfw; 12-30-12 at 10:35 AM. Reason: removed link
  #5  
Old 12-30-12, 10:35 AM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 4 Votes on 4 Posts
Do you have 24VAC between R and C at the control board? Remember that the door switch must be pushed in for power to go to the transformer.
 
  #6  
Old 12-30-12, 10:47 AM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 4 Votes on 4 Posts
  #7  
Old 12-30-12, 11:03 AM
D
Member
Thread Starter
Join Date: Dec 2012
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
Voltage reads about 26.3V AC. Does this mean the Control Board is okay, or is this inconclusive?
 
  #8  
Old 12-30-12, 11:12 AM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 4 Votes on 4 Posts
This means that if the control board does not give any diagnostic light and it has voltage that the control is failed.
 
  #9  
Old 12-30-12, 11:43 AM
D
Member
Thread Starter
Join Date: Dec 2012
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
So you're saying I need a new Control Board? Just verifying before I pitch out $100
 
  #10  
Old 12-30-12, 01:25 PM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 4 Votes on 4 Posts
This means that if the control board does not give any diagnostic light and it has voltage that the control is failed.



Read more: http://www.doityourself.com/forum/ga...#ixzz2GZZsTt9f
 
  #11  
Old 12-30-12, 01:42 PM
D
Member
Thread Starter
Join Date: Dec 2012
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
Okay, so what should I do? Where should I go from here? Any thoughts?

Sorry if I'm a bit dense. Got a lot of other stuff going on here at the homestead!
 
  #12  
Old 12-30-12, 02:56 PM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 6,244
Received 4 Votes on 4 Posts
The control is failed therefore it needs replaced.
 
  #13  
Old 12-30-12, 05:36 PM
D
Member
Thread Starter
Join Date: Dec 2012
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
By "control" you mean the control board, or some other part of the system?

Sorry to keep you coming back here so much for such stupid questions, I just don't want to get the wrong thing!

Thank you!
 
 

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