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 06-08-2011, 08:41 PM   #1
Newbie
 
Join Date: Jun 2011
Location: Middle of North Carolina
Posts: 4
Share |
Default

Headscratcher....Trane heatpump


Basics....unit is a Trane TWRO24C100A0 compressor and a TWHO24B140A1 air handler....been working for quite a while with no problems, but 2 years had a cap go...replaced cap and relay in the compressor, no problem until last winter....it quit while I was out of town working. Wife called local HVAC folks...they came out and put in a new Thermo (H-Well "PRO-3000) thinking that the old one had died (But apparently did no trouble-shooting as my wife wanted a programmable thermo anyway.) The tech wired the heat strips to be activated whenever the "Emerg. heat" setting was activated...got us thru winter but ouch on electric bill! This spring, switched over to air cond....no compressor activation! Tech has been out twice, said "Wiring bad between thermo and air handler". Huh?? I took thermo off wall, went under house and direct wired it to the A/H. Unit activates fan, no problem, but NO activation of compressor.

2nd visit tech says, "Fan control Board is bad...." So I got a new RLY02807 and installed. A/H fan works fine, but still won't activate the compressor. I did note that the LED on the defrost board in the compressor was not blinking as normal...tech says, "NO Big deal". I confirmed 24 VAC and proper AC to compressor (Push in relay and compressor runs...just RELAY not being activated).

WIfe is in NO MOOD to hear my tales of troubleshooting....she's in the "REPLACE THE D*^^ thing" MOOD. IF I had the $$, I'd do it just to keep the peace...but in the current economic climate, I"d REALLY like to get this thing running and get at least a few more years out of it....

Any hints, comments, or even a "HEY STUPID, REPLACE THE DA^^ thing?" Turning into a real head-scratcher for me....I'd really just like to know what the heck is wrong with it. More for my own knowledge and to tell the tech "Please look in this area."

A thousand thanks in advance!!!

Derswede

derswede is offline   Reply With Quote
Old 06-08-2011, 08:54 PM   #2
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Default

Headscratcher....Trane heatpump


So you took a meter and measured 24 volts between the low voltage leads on the contactor and it didn't pull in? If that's correct then replace the contactor.

Marty S. is offline   Reply With Quote
Old 06-08-2011, 09:29 PM   #3
Newbie
 
Join Date: Jun 2011
Location: Middle of North Carolina
Posts: 4
Default

Headscratcher....Trane heatpump


Quote:
Originally Posted by Marty S. View Post
So you took a meter and measured 24 volts between the low voltage leads on the contactor and it didn't pull in? If that's correct then replace the contactor.
Darn, forgot to include that point...have 24vac raw feed to the outside unit (compressor). Tech was saying, "NO 24V to outside unit" but it IS there...swapped defrost control boards with the upstairs compressor....board is good, runs fine in 2nd unit, but no blinking LED on board in first ("downstairs") unit....?? NO coil voltage to the unit's contactor....

Thanks for your comment...forgot to add that part about tech saying no 24V to outside unit...measured and checked twice. What controls the main contactor in the compressor....in other words, what is the activation sequence to activate the compressor motor?

Many thanks!
Derswede

Last edited by derswede; 06-08-2011 at 09:35 PM. Reason: added locationfor problem compressor.
derswede is offline   Reply With Quote
Old 06-09-2011, 06:11 AM   #4
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Default

Headscratcher....Trane heatpump


Should have 24v between r&c,Y&c and o&c at the heat pump terminal strip with a call for cool. If the pressure switches are closed then the board will send 24v to the contactor after a 5 minute delay. The blinking light is powered from r. Knowing which terminals you have 24v at would help a bunch.
Marty S. is offline   Reply With Quote
Old 06-09-2011, 09:13 PM   #5
Newbie
 
Join Date: Jun 2011
Location: Middle of North Carolina
Posts: 4
Default

Headscratcher....Trane heatpump


Quote:
Originally Posted by Marty S. View Post
Should have 24v between r&c,Y&c and o&c at the heat pump terminal strip with a call for cool. If the pressure switches are closed then the board will send 24v to the contactor after a 5 minute delay. The blinking light is powered from r. Knowing which terminals you have 24v at would help a bunch.

Marty,I bow deeply in your direction. That info should let me check thing and see if I or the Tech can ID the problem...MANY THANKS!
Derswede
derswede is offline   Reply With Quote
Old 06-11-2011, 10:07 PM   #6
Newbie
 
Join Date: Jun 2011
Location: Middle of North Carolina
Posts: 4
Default

Headscratcher....Trane heatpump


Hmmm...OK, I'm getting 24 VAC between the BL & YL wires into the defrost control board. I swapped the board with the working upstairs unit, so it is good. Also bypassed the load control setup to verify that it is not faulty.

Next step is to bypass the wiring to the compressor..Got the cable ready, but too many t-storms around this pm to let me finish. Still scratching my head,esp in that I STILL get no blinking LED on the defrost control board. I must be missing something (Other than my brain....)).

Derswede
derswede is offline   Reply With Quote
Old 06-12-2011, 05:21 AM   #7
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,389
Default

Headscratcher....Trane heatpump


But do you get 24 volts when measuring across R and BL?
beenthere is offline   Reply With Quote
Old 06-12-2011, 11:42 AM   #8
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,317
Blog Entries: 1
Default

Headscratcher....Trane heatpump


also there could be a sensor or pressure switch that is keeping the board from sending signal to contactor to pull in

__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Reply


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 TCONT803 Tstat install ... on Trane XB14 system chaaalie HVAC 10 09-08-2011 06:56 AM
Ruud vs Trane peter_holmes HVAC 23 07-28-2010 02:32 PM
York or Trane? koz HVAC 1 05-26-2010 05:42 AM
Need some friendly advice-- Coleman/York v. Trane biggerdaddynj HVAC 3 05-09-2010 10:46 AM
new install of Trane XL15i nind HVAC 32 01-30-2010 12:59 PM




Top of Page | View New Posts

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