Application
Heat Pump Controls
Compare thermostat options for heat pumps, auxiliary heat, and the staging your equipment requires.
Heat pumps need controls that match their compressor stages, reversing valve, and auxiliary heating arrangement. Start with the equipment model and existing terminal connections, then choose the scheduling and room-control features you want.
Product options
- PRO1 T721: local, non-programmable control for a heat pump with up to two heating stages and one cooling stage.
- PRO1 T721i: Wi-Fi and app programming for the same nominal heat-pump staging; this model requires a common wire.
- PRO1 T725: programmable control for a heat pump with up to two heating stages and one cooling stage.
- PRO1 T755WHO: a wireless room thermostat and equipment module for applications needing a separate equipment-side connection.
- Prestige IAQ YTHX9421R5085WW: a thermostat kit with an equipment interface module for more involved equipment and accessory configurations.
These products offer different staging and wiring arrangements. A two-heat rating does not mean two compressor stages: auxiliary heat can account for a heating stage.
The White-Rodgers 1F89EZ-0251, 1F83H-21NP and 1F83H-21PR provide documented heat-pump options with auxiliary heat. The Sensi 1F87U-42WF and Blue Easy Reader 1F95EZ-0671 also have model-specific heat-pump configurations. Compare compressor and auxiliary stages in each manual; these products are not interchangeable by brand or appearance.
Before selecting
Record the compressor stage count, auxiliary heat source, emergency-heat requirements, reversing-valve operation, and available thermostat conductors. Verify the exact model's wiring diagram and power supply. A dual-fuel system requires a documented control sequence for its heat pump and alternate fuel source; heat-pump support alone does not establish dual-fuel compatibility.
For room placement and wiring alternatives, see Wireless Thermostat Retrofits.
