Lennox furnace-code for open limit switch

Reply

  #1  
Old 01-30-16, 03:50 PM
Member
Thread Starter
Join Date: Jan 2016
Location: USA
Posts: 3
Lennox furnace-code for open limit switch

Hi, I have a lennox g40uh-36a-070-02 and have the code for open limit switch.
I have checked primary, secondary, roll outs, and pressure switches for continuity and all are good.

What can I be missing, or doing wrong?
Thanks
 
Sponsored Links
  #2  
Old 01-30-16, 04:41 PM
Member
Join Date: May 2015
Location: USA
Posts: 3,138
The limits will reset when they cool down, but the furnace will be locked out for an hour. Are you checking the limits right after the furnace shuts down?
 
  #3  
Old 01-30-16, 05:20 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 50,580
Likes Received: 108
If you are getting a code for an open limit than you missed one. Like Carbide said they will reset when they cool off. That means you need to check when it happens. I connect my meter to the control board and watch the limit from that location to see if one is actually opening.
 
  #4  
Old 01-30-16, 07:00 PM
Member
Join Date: May 2015
Location: USA
Posts: 3,138
And make sure your filter is clean and dampers are all open.
 
  #5  
Old 01-31-16, 07:18 AM
Member
Thread Starter
Join Date: Jan 2016
Location: USA
Posts: 3
I found a loose wire at 12 pin! Looks like I got it licked!
Thanks guys
 
  #6  
Old 01-31-16, 09:06 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 50,580
Likes Received: 108
That is a very common problem. Glad you got it fixed.
 
Reply

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