Honeywell Wi-Fi Thermostat 9000 - Conventional System Wiring Guide; 1 H;1 C and Cool-only Systems; 2 H;2 C and Heat-only Systems

33-00235 4
1H/1C System
(1 transformer)
Rc Power [1]
R [R+Rc joined by jumper loop]
Y Compressor contactor
C 24VAC common
W Heat relay
G Fan relay
Heat-only System
Rc Power [1]
R [R+Rc joined by jumper loop]
C 24VAC common
W Heat relay
1H/1C System
(2transformers)
Rc Power (cooling transformer) [1, 2]
R Power (heating transformer) [1, 2]
Y Compressor contactor
C 24VAC common [3]
W Heat relay
G Fan relay
Heat-only System
with Fan
Rc Power [1]
R [R+Rc joined by jumper loop]
C 24VAC common
W Heat relay
G Fan relay
Wiring
Wiring Guide — Conventional Systems
NOTES
Wire specifications: Use 18 to 22-gauge thermostat wire. Shielded cable is not required.
[1] For power supply, provide a means of disconnection and overload protection.
[2] Remove jumper loop for 2-transformer systems.
[3] Common connection must come from cooling transformer.
Wiring Instructions
1. This thermostat requires a 24VAC common wire to power-up. The K terminal is available
for Wiresaver module (THP9045A1023).
2. Straighten the wire. Using a pen’s tip, hold down the terminal and gently slide the wire
into the terminal hole.
Note: Terminal hole will only accept one wire.
Jumper Loop
Cool-only System
Rc Power [1]
R [R+Rc joined by jumper loop]
Y Compressor contactor
C 24VAC common
G Fan relay
2H/2C System
(1 transformer)
Rc Power [1]
R [R+Rc joined by jumper loop]
Y Compressor contactor (stage 1)
C 24VAC common
W Heat relay (stage 1)
G Fan reay
W2 Heat relay (stage 2)
Y2 Compressor contactor (stage 2)
2H/2C System
(2 transformers)
Rc Power (cooling transformer) [1, 2]
R Power (heating transformer) [1, 2]
Y Compressor contactor (stage 1)
C 24VAC common [3]
W Heat relay (stage 1)
G Fan relay
W2 Heat relay (stage 2)
Y2 Compressor contactor (stage 2)
See [notes] below