Lennox G40UH Gas Furnace help - http://www.hvacmechanic.com/ Forums

Original message

needhelp 2

76.209.227.183

"Lennox G40UH Gas Furnace help" , posted Tue 9 Sep 23:16

Hello,

I have a newly installed Lennox G40UH gas furnace. As soon as I turn on the digital thermostat to call for heat, the fuse would blow out (this is the second time it'll be replaced). There was a spark on the thermostat when I turned it on. Can anyone suggest on how to correct this problem?

Thanks in advance for your help.

Replies:

mebruce77

142.161.77.249

"Re(1):Lennox G40UH Gas Furnace help" , posted Thu 2 Oct 00:44

If you want to check things yourself rather than make the call to the installers I would start with the thermostat wires. Observe the color of each wire on the back of the stat and the terminal it's on and do the same at the furnace. Sounds like there's a dead short somewhere. I once had a similar situation and after over an hour of diagnosis found that someone had put a drywall screw through the low voltage wire. Let me know how this goes. I happen to have a G40 in my own house.

I'm the Fixer...and the fixin' gets done!

learner

70.73.177.71

"Re(1):Lennox G40UH Gas Furnace help" , posted Wed 10 Sep 02:07

Hi,
Why bother? It must be under warranty. If you mess with it warranty may be void.

needhelp 2

76.209.227.183

"Re(1):Lennox G40UH Gas Furnace help" , posted Wed 10 Sep 00:04

I'm definitely calling them. This is the second time the fuse blew out. I just want to get some idea why this keeps blowing out. The technician said that everything looked fine when it blew out the first time.

acefurnacefxr

70.226.6.113

"Re(1):Lennox G40UH Gas Furnace help" , posted Tue 9 Sep 23:42

newly installed...........i would not be on the internet looking for answers..ide be on the phone to the ppl who installed it......

HVAC REPAIR IS NOT A DIY WEEKEND PRODJECT

I have been performing HVAC repairs for 23 years

http://www.barackobama.com

K-Man

170.153.212.251

"Re(2):Lennox G40UH Gas Furnace help" , posted Thu 11 Sep 12:22

I had just built a house recently where there was a newer model Lennox, forget which, and was trying to hook up the tstat wires at the control board and I blew that purple buss fuse. I found them at Autozone for like $2.50 a box, replaced it, and didn't see it happen again after, but I sold it and have moved on.

But this resonated with my recent experience and thought that was interesting enough to comment.

Nick