Trane XL80 Won't fire


  #1  
Old 02-06-12, 12:27 PM
P
Member
Thread Starter
Join Date: Jan 2007
Location: United States
Posts: 13
Upvotes: 0
Received 0 Upvotes on 0 Posts
Trane XL80 Won't fire

Hello everyone. I have a Trane XL80 with an electronic ignition in a commercial building. It stopped working and I am trying to figure
out why. When it calls for heat, the fan comes on but nothing else happens. The ignitor appears to be in good condition, and I checked it for continuity and it doesn't have much resistance. But I don't really know how to check it properly. I checked MV/PV voltage and got 90v. I replaced the S8610U Honeywell Ignition module in the beginning and that didn't help. It seems to me the ignitor isn't getting hot, so the gas valve doesn't open and nothing happens. I should also say it was probably installed around 1986

I'd appreciate any insight you may have, I'd like to test components with my meter if that is possible. Thanks!
 
  #2  
Old 02-06-12, 01:17 PM
SeattlePioneer's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2007
Location: Seattle, Wa
Posts: 4,469
Upvotes: 0
Received 1 Upvote on 1 Post
>

I presume you are talking about the inducer motor fan that circulates the combustion gases through the furnace?


Check to see if the pressure switch is closing.
 
  #3  
Old 02-06-12, 01:23 PM
P
Member
Thread Starter
Join Date: Jan 2007
Location: United States
Posts: 13
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks! How do I check it? By sucking on it? Or can I bypass it? I believe that is the fan I am talking about, it is right on the unit.
 
  #4  
Old 02-06-12, 04:03 PM
SeattlePioneer's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2007
Location: Seattle, Wa
Posts: 4,469
Upvotes: 0
Received 1 Upvote on 1 Post
Use multimeter to check the voltage on each side of the switch. One side should have about 24 VAC to it whenever the inducer motor is running and the other side should have 24 VAC to it after the inducer motor spools up and applies enough negative pressure through the rubber tubing.

If it doesn't close, the next stage of heating the hot surface ignitor wont occur.


If the pressure switch does close, inspect the HSI for a visible crack that prevents it from heating up. If it's cracked it needs to be replaced.
 
  #5  
Old 02-06-12, 04:43 PM
P
Member
Thread Starter
Join Date: Jan 2007
Location: United States
Posts: 13
Upvotes: 0
Received 0 Upvotes on 0 Posts
I did inspect the HSI and it didn't seem to be vracked or burnt, thanks for the instruction! I'll check the switch tomorrow, can I bypass it to check it?
 
  #6  
Old 02-07-12, 10:57 AM
P
Member
Thread Starter
Join Date: Jan 2007
Location: United States
Posts: 13
Upvotes: 0
Received 0 Upvotes on 0 Posts
New info, the blower that was running was the one to blow the heat. The induction blower is not working and 120V is being sent to it. The blower is a FASCO 7121-6376. Anyone know the best place to get one? I am assuming that is what I need. Thanks for any help.
 
  #7  
Old 05-31-12, 03:53 AM
P
Member
Thread Starter
Join Date: Jan 2007
Location: United States
Posts: 13
Upvotes: 0
Received 0 Upvotes on 0 Posts
The induction blower fixed the problem. The fan was junk inside it so it would not activate the pressure switch. I hope this helps someone.
 
 

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