Choosing the correct thermostat for a heat pump application all depends on what kind of heat pump system you are working with. A lot of thermostats will say "heat pump thermostat". This usually indicates it will work for a geo type system, where backup heat will come on as needed and support the geo. A lot of people are dealing with dual fuel heat pumps, which is whole other animal. In dual fuel applications we need to be able turn the compressor and use the the furnace or electric heat strip to come on at a certain outdoor temperature. Below is a list of stats for each application. Check out wiring diagrams section for wiring help.

Dual Fuel Thermostats:

HW TH8321WF1001- Wifi Dual fuel option, Does not require outdoor sensor, uses WiFi for outdoor temperature.

HW TH8320R\TH8321R - Dual fuel option, requires outdoor sensor. C7089R1013 Wireless Redlink or C7089U1006 Wired. *

HW TH8320R\TH8321R W/ THM5421R1021 Equip Interface module-  Dual fuel option, can be wireless or two wire, two wire allows stat to be powered requires outdoor sensor.

C7089R1013 Wireless Redlink or C7089U1006 Wired. *

*- Redlink Accessories Require 24VAC to Thermostat

THX321WF - Uses wifi or sensor C7089U1006 for outdoor temperature

TH6320WF - Uses wifi or sensor C7089U1006 for outdoor temperature

Th6220U - Uses wired sensor C7089U1006 for outdoor temperature

WR Sensi thermostats- Uses internal algorithm for dual fuel applications.Basically times the heat pump.

WR 1F97-1277**, 1F95-1291 **, 1F95-1277**, 1F95-0680 Commercial, 1F85U42PR, 1F85U-42NP- All these will run duel fuel with logic

**- Can use 1F145-1378 Outdoor Sensor

NEST Thermostats- Uses WiFi for outdoor temperature. Be sure to have a common for this thermostat.

Ecobee- Uses WiFi for outdoor temperature.

Pro1 T755-  Uses Logic for Dual Fuel Staging.