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

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 05-25-2012, 09:13 PM   #1
JND
Newbie
 
Join Date: May 2012
Posts: 2
Rewards Points: 10
Default

Trane XE78 Furnace coupled with Trane 1000 AC


Trane XE 78 furnace coupled with Trane 1000 stopped working all together after running the AC one time. Everything worked overnight but stopped by the next morning. Wife heard a noise come from the AC unit (she says) that night. The furnace has the LED indicator that has no flash. No blower fan either. We used the furnace all winter, by the way, with no issues. I have checked incoming power to both units and all is fine there. Panel pressure switch is making also. Seems the AC unit is the culprit but logic tells me that if there was an issue with it then the breaker would have done its job and tripped before reaching the furnace. Both breakers for each unit were on when inspected. Control board is a Whites Rodgers 50A50. Ran a resistance test on the thermo and checked out. I also tried to jump the blower fan straight from the thermo by connecting red and white no fan. Had power to the transformer to controller but no power out of controller. What would cause it to blow?

JND is offline   Reply With Quote
Old 05-26-2012, 01:36 AM   #2
REP
Member
 
Join Date: Jul 2011
Posts: 615
Rewards Points: 500
Default

Trane XE78 Furnace coupled with Trane 1000 AC


One thing is by jumping the red and white your furnace should have come on unless you are using your own coloring system.

REP is offline   Reply With Quote
Old 05-26-2012, 09:09 AM   #3
JND
Newbie
 
Join Date: May 2012
Posts: 2
Rewards Points: 10
Default

Trane XE78 Furnace coupled with Trane 1000 AC


Just the standard colors. Red and white - furnace & green for the AC. I am a little confused about the blower running if it comes after the controller electrically. Essentially I would be sending 24v back to a dead board. Looking at it, the blower would get a signal from the board even though it's high voltage it is still being monitored by the board correct? Still, I don't know what caused the system shutdown. I did those test just to occupy the simple ideas. Also I do not see any direct shorts in the system. Another thing that bothers me is that there are not any fuses for the low voltage after the xformer.... Logic is that high voltage needs to be broken from inline before reaching low voltage, xformer or not. Redundancy seems lacking. Where would a fuse be? Checked the wiring harness for an inline fuse and also checked in the moler plug for one but nothing. AirTron put this dude in 20 yrs ago but fuses have been around far longer than that? Any ideas would likely be entertained before I go replacing parts that are bound to blow again without finding cause.

Last edited by JND; 05-26-2012 at 11:12 AM. Reason: Lack of explanation
JND is offline   Reply With Quote
Old 05-26-2012, 03:53 PM   #4
REP
Member
 
Join Date: Jul 2011
Posts: 615
Rewards Points: 500
Default

Trane XE78 Furnace coupled with Trane 1000 AC


You have a very standard furnace and a/c unit.You should have 5 wires from the furnace to the stat and two wires from the furnace to the outdoor unit.
On a call for cooling the stat will send power to a relay to send power to the outdoor unit which should power the contactor which allows line voltage to power the outdoor fan and compressor and at the same time run the furnace fan motor.
There is a wiring diagram on the furnace blower door panel.Once you take the front cover off the furnace you must tape the panel switch down in order to use a meter to check each item that should get power.
REP is offline   Reply With Quote
Reply

Tags
furnace blower, furnace control board, hvac operation, hvac repaire


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Trane XR90 - Condensate Drane Trap JDWorks HVAC 16 02-07-2012 07:59 PM
XL80 Trane Furnace Fan won't turn on jenlou HVAC 4 01-26-2012 05:59 PM
Trane Gas Furnace - blower on but no flame at burners herbert8101 HVAC 2 09-24-2011 08:23 PM
trane furnace with inducer blower error tjh57 HVAC 1 10-22-2006 07:45 PM
Help TRANE XE-80 furnace squeed HVAC 12 10-08-2006 08:22 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.