Wiring/Programming of a Honeywell TH8320 Thermostat
 

I recently purchased a Honeywell TH8320 programmable thermostat to bring a little energy efficiency to my new home. I have a Carrier 25HBA3 Base Series split system heat pump with a unit outside, and one indoors (installed up in the attic space above my garage). I detached the previous thermostat and made note of the wire colors and connections, and followed the instructions in the Honeywell manual to the best of my understanding, though I am not finding success in getting the heater to operate.

Here are the connections as per the previous thermostat:

W* --
O -- White Wire
G -- Green Wire
R -- Red Wire
C -- Blue Wire
Y* -- Yellow Wire

*There is a small length (about 1.5") of green wire that seems to be acting as a jumper going from the W terminal to the Y terminal.

When I try connecting my Honeywell TH8320, I am not able to get the heat to turn on. I did something last night that had heat coming on when I had it set to cool, but I decided to completely disconnect all wires from their terminals and start from scratch, though to no avail.

Based on my heat pump, I am assuming that it is a 1H/1C Heat Pump with no auxiliary heat, though perhaps I am mistaken.

My connections to the Honeywell terminal are as follows:
RC and R are connected by a jumper, with the red wire from the wall connected to the R terminal.
C -- Blue Wire
Y -- Yellow Wire
G -- Green Wire
O/B -- White Wire
The small length of green wire is connected to both the Y terminal and the O/B terminal (Since for conventional systems, it shows that the O/B terminal is actually the W terminal).

As for programming, I have the following:
0170 (System Type) = 2 - 1H/1C Heath Pump (No Aux Heat)
0190 (O/B Terminal) = 1 - O/B Terminal controls valve in heating

I think I am so close to having this correct, and I am seeking a little help to get me to a more energy efficient home. Thank you for any assistance and guidance!

:huh:

If you want to use that jumper, put your old stat back on.

If you want to use the new stat, wire it as per its directions.

NO jumper from O/B to Y.

On Carrier, O/B does NOT control valve in heating.

This is where I'd start.
From my research just this past weekend installing an Aprilaire 4400 air cleaner I had to refresh myself of the colored wires of my thermostat.

W-Controls heating
Y/O-Controls AC (O-heatpump only)
R-Power (RC/Cooling Power & RH/Heating Power) Mine has jumper
C-Common Ground
G-Fan

I also have switches on the back of my thermostat for: Heating system selector, Furnace or Heat Pump selector, & Auto Recover selector.

Consult your manual. :thumbup:

The TH8320 has no switches.