18-AC74D1-4
13
11.2 Low Voltage Hook-up Diagrams
Red
Yellow
Green
White
Black
Blue
W1
W2
B
G
Y1
Yellow
Yellow
Blue
Blue
R
Comfort Control
Air Handler
Air Conditioner
W1
W2
W3
G
Y
B
BK
Y
LO
R
Neatly bundle all low voltage
wires behind the service
valve cover as shown.
Notes:
1. If electric heat does not
have 3rd contactor (CH),
connect a jumper wire
from W3 to W2. If electric
heat does not have 2nd
contactor (BH), connect
a jumper wire from W2 to
W1.
2. Ylo and BK may not be
present on unit.
Air Handler
Hook-up Diagram
Notes:
1. If single stage
heating thermostat
is used, jumper
W1-W2 on furnace
terminal strip.
Comfort Control
Variable Speed
Furnace
Air Conditioner
Neatly bundle all low voltage
wires behind the service
valve cover as shown.
Red
Yellow
Green
White
Blue
W1
B
G
Y1
R
W1
W2
G
B
O
BK
Y
R
Yellow
Yellow
Blue
Blue
Black
W2
Y
LO
Variable Speed Furnace
Hook-up Diagram
