Complete System Failure After Storm Please Help. - HVAC - DIY Chatroom Home Improvement Forum

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


Thread Tools Display Modes
Old 05-21-2013, 02:24 PM   #1
Join Date: May 2013
Posts: 1
Rewards Points: 10

complete system failure after storm please help.

Hello, I had my Trane XR90 running fine, two days ago we had a storm and the power flickered a few times briefly, then went out for about 2 minutes. I didn't think anything of it, the air was back on. I noticed it was REALLY getting cold in the house in early morning. When I got home from work the house was HOT! I went to the thermostat, completely dead.

It's a digital one, now the screen is blank, the buttons do not work, I changed the batteries 3 times, still nothing. I figured it had froze up so I went to check. The outside was indeed frozen over, and the lines in the house were dripping wet, the black foam insulated jacket was soaked, all 10 feet of it was wet and dripping. There is power to the furnace junction box inside the unit (black and white) wires to the door switch and control board.

The red light is not on at all, I tried crossing the red and white, and red and yellow wires at thermo, and inside unit, while pressing door switch. Nothing.
I have a breaker for the unit in panel, and its fine. I checked the cap on condenser, I have not used a meter yet just visual check. No swelling, no leaking. It was just replaced last summer.

I could not find any breaker or fuse on outside unit, the wires and copper just run inside, I thought it would have a breaker on the house, or inside it......

So no spin up, no flame, no pilot, no response of any kind from thermo, main unit, or outside unit. Any ideas? My thermo has R, W, Y, G, Blue(C) wires. I tried to install a new thermo but it didn't have a terminal for C. I put the blue wire in B terminal at first, I hope I didn't hurt anything doing that.

Oh, and the board looks fine, a little golden brown color in a couple spots but no obvious burns, or broken solder connections, no burnt lines or paths.. It did have that sweet burnt smell a little when I first looked in there. I'm getting voltage reading from Xformer OK.

Thanks for the help sorry it was so verbose, but didn't want to leave anything out.



unknown0rigin7 is offline   Reply With Quote
Old 05-21-2013, 02:34 PM   #2
Hvac Pro
yuri's Avatar
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 16,129
Rewards Points: 396

#1 there should be a red light on the board but you need to hold the door switch in or tape it in to get power to the board.
#2 you should be getting 24 volts AC from R to C on the board if not look carefully at the board and there usually is a 3 or 5 amp GM plastic auto fuse on it somewhere or a glass one after the transformer and inline with the board in a plastic holder. Sounds like the board may be fried if it had a sweet smell. should have no smell at all and that may be why no red light. You should get 24 volts AC from the downstream/secondary side of the transformer or it got burnt out. Check that also.
#3 not sure if putting the blue wire on B was a good idea. it may be for a heat pump reversing valve and did no damage but take it off anyway and get a Honeywell Focus Pro tstat from HDepot as it can use the C


"Cut it twice and it is still too short".

Last edited by yuri; 05-21-2013 at 02:53 PM.
yuri is offline   Reply With Quote
Old 05-21-2013, 05:10 PM   #3
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,426
Rewards Points: 1,208
Blog Entries: 1

if it is froze up and you say it got really cold first, then PART of your problem may be that the contactor for the compressor welded itself shut from the brown out.
hvactech126 is offline   Reply With Quote

ac trane xr90

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
Need Help Buying a Sediment and Water Softener System. vpr80 Plumbing 10 02-23-2012 10:26 AM
New system, are my ducts adequate? civiltoatee HVAC 67 10-19-2010 04:06 AM
Wood Stove, and Furnace hot water system shendog HVAC 7 10-04-2010 09:30 PM
New House, new system, poor cooling Faulknertw HVAC 15 07-08-2008 10:06 PM
Size A/C system properly 70stang HVAC 1 03-26-2006 07:22 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1