Lennox P-8-9490 Transformer Burned Out - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 07-04-2011, 08:20 AM   #1
Join Date: Jul 2011
Posts: 1
Rewards Points: 10

Lennox P-8-9490 Transformer Burned Out

Two days ago I discovered my AC no longer working. The house thermostat indicated it was not receiving any voltage. I traced this back to the blower transformer which was not sending out any voltage. Input to the transformer was proper (110V).

Yesterday, in a pinch because of the holiday, I installed a Honeywell 25V 40VA transformer which I expected to work until I could get a replacement P-8-9490 transformer. The Honeywell also burned out. Is there any reason for the Honeywell to also burn out?


Harbicide is offline   Reply With Quote
Old 07-04-2011, 11:37 AM   #2
An old Tradesmen
Join Date: Oct 2008
Location: Somewhere
Posts: 34,594
Rewards Points: 8,174

You have a short that is burning out the transformers. must fix short before installing another new transformer.


beenthere is offline   Reply With Quote
Old 07-04-2011, 04:57 PM   #3
Hvac Pro
yuri's Avatar
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 16,127
Rewards Points: 392

check the wires to the outdoor unit. may be damaged from weed whacker, dog chewing, brittle and insulation missing and shorting.

also I would splice a 3 or 5 amp GM auto type fuse with blade terminals into the wire from the trans/secondary low voltage side so the fuse pops while you are short searching. can attach the wire to the fuse with spade type stakons from radio shack or the auto parts store.
"Cut it twice and it is still too short".
yuri is online now   Reply With Quote

Thread Tools
Display Modes

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wiring Tradeline L6006C Aquastat to Lennox CBWMV Hydronic Air Handler VIPSpecialNeeds HVAC 5 03-15-2010 06:37 PM
Unable to find out how to wire a dimmable light transformer Maleko Electrical 9 02-07-2010 01:07 AM
Lennox 80MGF Board Burned out jay235 HVAC 4 12-08-2009 09:23 AM
How to install Aprilaire transformer? Studly HVAC 9 09-18-2009 09:44 AM
lennox 120-24v transformer zammy HVAC 5 08-08-2009 06:01 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1