Honeywell Thermostat: TH8320U
Re: ADD-ON HEAT PUMP
The TH8320U VisionPro thermostat is capable of direct-control of an add-on heat pump system. (Does not apply to York units with Yorkguard Module)
Requirements:
- TH8320U Thermostat
- C7089U Outdoor Sensor
- Minimum #8 (preferably #10) stat wire between Heat Pump & Furnace
- Minimum #8 (preferably #10) stat wire between Furnace & Thermostat
CONFIGURE THERMOSTAT:
- Enter "Installer Setup".
- Modify the items in the chart below.
- Press "Done" to exit "Installer Setup" and save changes.
| Setup# |
Description |
Value |
Description |
| 170 |
System Type |
7 |
2Ht/1Cl Heat Pump |
| 190 |
Reversing Valve |
0 |
Cooling Changeover |
| 200 |
Backup Heat |
1 |
Gas |
| 210 |
Fossil Fuel Control |
0 |
Thermostat-Controlled |
| 340 |
Remote Sensor |
2 |
Outdoor for Control |
| 350 |
Compressor Lockout |
40 |
40 Degrees |
WIRING:
| Thermostat |
Furnace |
Heat Pump |
| R |
R |
R |
| C |
C |
C |
| G |
G |
|
| W/Aux |
W |
W or W1 or 66 or X (Trane) |
| Y |
Y or Y/Y2 |
Y |
| O |
(wire nut) |
O |
| S1 |
(wire nut) |
O/D Sensor 1 |
| S1 |
(wire nut) |
O/D Sensor 2 |
SEQUENCE OF OPERATION:
Cooling Mode
- Thermostat energizes "O" whenever the mode is "Cool'
- Thermostat energizes "Y' and "G" when there is a demand for cooling.
Heating Mode
- When the outdoor temperature is above 40 deg (adjustable Setup# 350) the thermostat will energize "Y" and "G" when there is a demand for heating.
- When the outdoor temperature is below 40 deg (adjustable Setup# 350) the thermostat will energize "W" when there is a demand for heating.
Em Heat Mode
- The thermostat will energize "W" when there is a demand for heating.