Wiring Diagram Thermostat Honeywell. S indoor and outdoor wired sensors. If you check the honeywell thermostat ct31a1003 wiring diagram youll see that it requires only two wires because its a very basic thermostat designed only to control a heating system.
If you have a system that both heats and cools your house you need a more complex thermostat with more wire terminals and if your system incorporates a heat pump you need. Mounting plate with four wires of the honeywell large dial thermostat model t87n1026. If you have a two stage heat pump then you will also utilize terminal y2 for the second stage.
The t3 series of programmable thermostats provide sophisticated automatic control of domestic heating systems.
The t3 series of programmable thermostats provide sophisticated automatic control of domestic heating systems. Honeywell thermostat wiring diagram 4 wire source. If you have a two stage heat pump then you will also utilize terminal y2 for the second stage. Contains all the essential wiring diagrams across our range of heating controls.