Honeywell Home Thermostat Wiring Schematic Wiring View and Schematics

Thermostat Red Wire. How To Wire Your Thermostat Home Or Office Red wires are 'hot' because they connect to the power source. Without a connection to the red wire, your thermostat will not have a power source

Nest 3 Wire Installation
Nest 3 Wire Installation from diagrampaielliqx.z21.web.core.windows.net

Attach the Yellow wire to the Y terminal for AC/cooling mode If that's the case, the thermostat will have RH wires (heating power) and RC.

Nest 3 Wire Installation

The red wire (R wire) is your power wire that connects to the transformer in your heat pump or AC to power the thermostat If that's the case, the thermostat will have RH wires (heating power) and RC. All air conditioner thermostats have a red wire for power

My new thermostat has two black and two red wires and old has two black. Orange - This wire connects to your heat pump (if you have one) One is for cool and the other is for heat, hence the abbreviation "RH" and "RC"

Ac Thermostat Wire Colors. Attach the Green wire to the G terminal for the Fan The orange wire only applies to homeowners who have an air-source heat pump