Honeywell CT87A round Installation Instructions Manual page 7

Fig. 8–(CT87A for a 2-wire heating only system)
R
Fig. 9–(CT87A for a 3-wire hot water heating only system)
R
Fig. 10–(CT87B for a 4-wire heating/cooling system)
R
R
C
JUMPER R TO R
H
CT87A,B,J ROUND® THERMOSTAT
Y
W
Y
W
G
H
Y
W
C
7
CT87A WALLPLATE
POWER
TO
SYSTEM
HEAT
M20183
.
CT87A WALLPLATE
WIRE LABELS
(LETTERS
ON ORIGINAL
THERMOSTAT
TERMINALS)
R
3-WIRE
W
HOT WATER
ZONE VALVE
B
M20184
.
CT87B SUBBASE
POWER
FAN
SYSTEM
COOL
HEAT
M20185
TO
69-0274-5