Wiring a Honeywell ProVision TH8321U1006, upgrade from Weathertron Tstat
 

Saw this link, but didn't answer my question unfortunately:
http://www.diychatroom.com/f17/honey...erences-13121/

I hope I didn't get in over my head. I'm normally pretty good fixing things around the house but I'm at a loss with this wiring and am hoping some experts here can save me :) I'm trying to a) confirm the details of my HVAC system and then using that knowledge to b) determine how to wire a new thermostat for that unit. Here's everything I know, thanks for the help!

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Outdoor Unit:
- Built Sep 1999, Split Sys Heat Pump
- Outdoor Model / Serial Num: XE1000 TWR024C100A5 / P29IT3J4F?
- Indoor Model / Serial Num: TWG025A140B0 / P374NF91Y
- Indoor Heater Model: BAYHTR1410

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What I don't know, which impacts the wiring:
1) I think it's dual stage, but cannot confirm?
2) I think its a single compressor (not two) but again am not sure?
3) Unsure if it is a 2H/1C (w/Auxillary Heat), 2H/2C (w/o aux heat), 3H/2C (w/ aux heat). NOTE: The existing Weathertron thermostat has a light for Aux Heat and another light for Emergency Heat if that helps.

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Existing Thermostat Details:
- Weathertron BAYSTAT239A
- Wiring NOTE: From what I've read, I think the original installer didn't have enough wire and reused colors / wires. To explain there is a single strand of 5 wires coming out of the wall (white / red / yellow / green / blue), and then 3 more separate (*blue* / *white* / *green*) which I've indicated with an asterisk to show the difference below. Also note that this second green wire was not wired to any terminal.

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(Terminal = Wire color)
X2 = *Blue* wire
B = *White* wire
W = White wire
R = Red wire
Y = Yellow wire
G = Green wire
O = Blue wire
T = <no wire>
U = <no wire>
F = <no wire>

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New Thermostat: Honeywell VisionPro TH8321U1006
3 possible terminal configs depending on HVAC system per questions above:

1) 2H/1C (w/ aux heat)
L = Equipment monitor
E = Emergency heat relay
Aux = Aux heat relay
Rc = Power
R = (R + Rc joined by jumper)
O/B = Changeover valve
Y = Compressor relay
G = Fan relay
C = 24VAC common
S1 = Optional outdoor / remote sensor
S2 = Optional outdoor / remote sensor


2) 2H/2C (w/o aux heat)
Y2 = Compressor 2 relay
Rc = Power
R = (R + Rc joined by jumper)
O/B = Changeover valve
Y = Compressor 1 relay
G = Fan relay
C = 24VAC common
S1 = Optional outdoor / remote sensor
S2 = Optional outdoor / remote sensor


3) 3H/2C (w/ aux heat)
Y2 = Compressor 2 relay
L = Equipment monitor
E = Emergency heat relay
Aux = Aux heat relay
Rc = Power
R = (R + Rc joined by jumper)
O/B = Changeover valve
Y = Compressor 1 relay
G = Fan relay
C = 24VAC common
S1 = Optional outdoor / remote sensor
S2 = Optional outdoor / remote sensor


Thanks for the help!

That was hard to read. The instructions on the manual are pretty straight forward, but if are having problems, you should call the customer support people during normal business hours (Minnesota). Perhaps someone can help on-line, but it's kinda hard to help with that question in this manner. Good luck.

Thanks for the reply, to your comments:

1) It was hard to read: Agreed. For some reason it took out all the white space on the initial post, readded for readability
2) Straightforward: The install instructions for the new thermostat are, however not knowing a) the actual characteristics of my system to know which wiring diagram is applicable and b) what the current wiring to terminals on my Weathertron stands for, makes that translation guess work at best.

If you have any other ideas, feel free to let me know. Customer support is an option, but I'm keeping that until last given some bad experiences in the past. I find I get better answers on forums like this. Thanks again!

First let me say this: I am not there, so it is hard to say what is correct without actually seeing the wiring and connections.

The x2 connection on the existing stat is the common you should connect the x2* wire to the common tab on the new stat. There is a factory jumper on the stat, keep that jumpered, and wire r to r. Basicly, just swap the existing r, w, y, g, & o connections. In addition, you want to jumper the e/aux to the w terminal on the stat.

Odds are that you have two stage heat & one stage cool setup. Good luck and feel free if you have any other questions to ask

I understand, troubleshooting something without seeing it is extrememly difficult, I appreciate the attempt. Prior to getting your response I got an answer on another forum to this question that matched up very closely to yours (see below). One deviation however was your recommendation to jumper E/Aux to the W terminal - was curious as to what that is for? I have wired the Tstat per the below and can add that jumper if needed. Currently the Tstat seems to be operating as expected, but I have not had the opp to test every scenario.

Thanks again for your time, it is appreciated.

<Other forum response>
E = *Blue
Aux = White
Rc & R = Red (use supplied jumper)
O/B = Blue
Y = yellow
G = green
C = *White

Set option 170 to 7
option 190 = 0

Jumpering aux/E to W2 will bring on the emergency heat when the house temp drops about one degree. When turned to emergency heat.

Without that jumper. The indoor temp will drop 2° before the heat comes on, in emergency heat.

Actually, there are a couple of deviations. I believe your *blue wire is a common. If you set system to e-heat, you will have a short from r-common which should blow the fuse. If I am not mistaken.