Lennox Whisper Heat damper and loud pop


  #1  
Old 01-06-11, 08:44 AM
J
Member
Thread Starter
Join Date: Jan 2011
Location: USA
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Lennox Whisper Heat damper and loud pop

I've got a Lennox Whisper Heat gas furnace, which occasionally makes a loud pop, or boom as it starts up. It's obvious this boom is coming from an accumulation of gas (although I don't smell any gas).

I had a technician come out to tune up the unit and he discovered that the damper isn't functioning properly. He tweaked it a little bit, but said he couldn't get it to close fully. Of course, while he was here, the furnace did produce the loud pop.

The pop only occurs when the furnace hasn't run in quite some time. For example, when the thermostat turns down to 65 at night. Also, every once in a while the unit will not start up. if I turn it off, then close the damper manually it will start (the damper is fully open at those times).

The technician said that the damper problem is probably causing the boom/pop. I've read that it's possible to remove the damper and jump the damper open proving switch.

My question is, do you think the damper problem could really be causing the gas build up?

Thanks!
 
  #2  
Old 01-06-11, 09:48 AM
J
Member
Thread Starter
Join Date: Jan 2011
Location: USA
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Broken spring

Turns out the spring was broken. I jumped the switch and the furnace is working fine now. Is there any downsides (besides the 2% efficiency gain) to running the furnace in this condition?
 
  #3  
Old 01-06-11, 05:39 PM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 16,984
Upvotes: 0
Received 0 Upvotes on 0 Posts
No, no harm of this. It was jsut Lennox over design system.
 
  #4  
Old 11-09-14, 04:34 PM
S
Member
Join Date: Nov 2014
Location: usa
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
I'm having a problem with the damper door also...the door tries to open or close (works sometimes) and I here clicking sounds and the door will try to open or close but occasionally it will get stuck.
I read the thread above but i'm not sure how to jump the switch. can someone give me any more info. could it be that the door needs to be lubricated....sometimes when it's is trying to open or close i can give it a little push real lightly with my finger and the operation will work.
Thanks.
 
  #5  
Old 11-09-14, 07:41 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 62,051
Received 3,419 Upvotes on 3,065 Posts
Welcome to the forums.

If it's a damper in the flue then it would appear that it must be blocked open. When you block it open..... the switch will be on.

I'll have the forum pro confirm.
 
  #6  
Old 11-10-14, 07:23 AM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,796
Received 50 Upvotes on 44 Posts
Don't jump the switch - it's there for a reason.

Sounds like the damper motor might be bad.
 
 

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