Changing Out Thermostats - HVAC - DIY Chatroom Home Improvement Forum

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


Thread Tools Display Modes
Old 05-05-2013, 02:45 PM   #1
Join Date: May 2013
Posts: 1
Rewards Points: 10

Changing out Thermostats

Ladies and Gentlemen:

We have a York system with a Honeywell Thermostat--T8195B; I'm trying to replace the (although still operating) thermostat with a Carrier Comfort Choice Thermostat--CFTCH.

The York furnace/blower has the following wiring:
Y1 - Nothing
Y/Y2 - Yellow
W - White
R - Red
G - Green
C - Blue

This is how I found the Honeywell wiring when I took it off the wall:
R - Red
C - Blue
G - Green
O - Nothing
B - Nothing
W - White
Y - Yellow

I'm starting to see a trend here that is also confirmed by more info on the web, but the Carrier unit (garage sale and didn't come with any paperwork) is lacking in how to wire it. When I open the Carrier thermostat I find the following pressed into the inside plastic cover, but not necessarily "close" to the connection terminals:

Then there is a sticker next to the connection terminals labeled from top to bottom: V+, VG, blank, blank, blank, blank.

Under that sticker next to the connection terminals, also pressed into the inside plastic cover from top to bottom:
C, B, blank, blank, S1, S2.

Then, on the back side of the Carrier circuit board there is factory stenciling for the prongs that slide into the connection terminals when the plastic case is closed. Labeling on that from top to bottom (that also corresponds to the connection terminals):
Comm/Pwr, Gnd, blank, blank, S2, S1
And yes, it appears like the S1 prong goes into the S2 terminal connector; and S2 prong goes into the S1 terminal connector.

I can't find any booklet, manual or installation guide that seems to correspond to my Carrier Comfort Choice (CFTCH...).
The only way I get power to the thermostat is by putting the red wire into the first/top connection terminal (this corresponds to the stencil on the circuit board), but to finish the circuit the next/second has to be either the Yellow or Blue wire. With the Green wire in spot #2 the fan comes on; with the White wire in spot #2 I get the furnace.

In all cases of any arrangement of wires (maybe missed some; getting tired) I will get an error code of "E1" in the Carrier thermostat which seems to be:
"E1—COMMUNICATION FAILURE. An E1 will be displayed
if the thermostat cannot communicate with the Utility
I/O board. Check and make sure V+, Vg, RS+, and RS- are
wired correctly between the thermostat and Utility I/O board.
This error message may sometimes take up to 30 sec before it
is displayed. After the problem has been fixed, cycle power to
ensure that all errors have cleared."

Well, I don't know how to take my five wires from my York coming out of my wall and hook them up into my garage-sale-acquired Carrier so my heat/cool actually work.

Thanks for any help. Cheers,


YJCMTSU is offline   Reply With Quote
Old 05-05-2013, 02:50 PM   #2
An old Tradesmen
Join Date: Oct 2008
Location: Somewhere
Posts: 34,625
Rewards Points: 8,236

Probably will need to post pics of the sub base and the thermostat for someone to be able to help you.


When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is offline   Reply With Quote
Old 05-05-2013, 03:35 PM   #3
FClef's Avatar
Join Date: May 2013
Location: Pennsylvania
Posts: 218
Rewards Points: 160

There are the manuals. Most of the time, even for "legacy" equipment (discontinued items) you can find support documentation on the company website.

Hope this helps.
FClef is offline   Reply With Quote

carrier , cftch , honeywell , t8195b , york

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
Using Two Thermostats Question tim2255 HVAC 9 01-03-2012 10:13 PM
Lutron Thermostats ChrisDIY HVAC 4 10-24-2011 08:45 AM
2 wire thermostats in parallel? DragonFire Electrical 11 01-22-2011 12:50 PM
Cheap suggestions for changing look of bathroom sink countertop? mrdazzo7 General DIY Discussions 11 01-07-2011 05:43 PM
Thermostats - Changing Spuds105 HVAC 4 10-23-2006 01:18 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1