SmartCommand Thermostat
Installation Manual
24
HVAC system wiring

Wiring will differ depending on if your system is a standard gas or electric system or if your system is a heat

pump system.

Standard HVAC system wiring

Figure 18 shows the wiring diagram for a standard gas or electric HVAC system. Wiring colors are typical

thermostat wiring color codes.

Note: For typical central heating/cooling systems, leave j umper JP1 installed. If you have separate heating and cooling
system transformers, cut jumper JP1. Wire RC to the cooling system transformer and RH to the heating system
transformer.
Figure 18. Standard HVAC system wiring
Note: Wire R to either RH or RC for common transf ormer HVAC systems.
C 24 VAC common
R 24 VAC return
W1 Heat stage 1
W2 Heat stage 2
G Fan
Y1 Comp stage 1
Y2 Comp stage 2
Thermostat
connections
Standard HVAC systemThermostat control unit
SW1
HP
STD 1
S2 2
OFF ON
J4
HVAC system
JP1
FUSE
24V COM
24V RH
24V RC
W1 Heat 1
W2 Heat 2
G Fan
Y1 Comp 1
Y2 Camp 2
Red (RH)
Red (RC)
White
Orange
Green
Yellow
Black