Fig. 13—Two-Speed Heat Pump with Typical
Fan Coil
A94226
24 VAC HOT
FAN
HEAT STAGE 3
COOL/HEAT
STAGE 2
RVS COOLING
COOL/HEAT
STAGE 1
R
G
W/W1
Y/Y2
O/W2
Y1/W2
R
G
24 VAC COMM.
RVS HEATING
TROUBLE
OUTDOOR
SENSOR
CONNECTION
C
B
L
S1
S2
C
Y2
C
W2
R
O
Y1
W3
L
MODEL 2S
THERMOSTAT
TYPICAL
FAN COIL
TWO-SPEED
HEAT PUMP
See note 7
W2
Y/Y2
O
*
Y1 *
*
L
E
*
W3
Fig. 14—Single-Speed Heat Pump with FK4B
Fan Coil and Special 3-Stage Electric Heat
A94275
24 VAC HOT
FAN
HEAT STAGE 2
COOL/HEAT
STAGE 1
RVS COOLING
HEAT STAGE 3
R
G
W/W1
Y/Y2
O/W2
Y1/W2
R
G
24 VAC COMM.
RVS HEATING
TROUBLE
OUTDOOR
SENSOR
CONNECTION
C
B
L
S1
S2
C
Y
C
R
O
W2
MODEL 2S
THERMOSTAT
FK4B
FAN COIL
SINGLE-SPEED
HEAT PUMP
See note 8
W2
Y/Y2
O
W3
L
E
Y1
WIRING DIAGRAM NOTES:
1. On AC models (1-stage cool, 1-stage heat), O/W2 is not
connected. Furnace must control second-stage heat. Refer to
furnace instructions for proper setup.
2. On HP models (1-stage cool, 2-stage heat), O/W2 can control
second-stage heat. Refer to indoor unit instructions for proper
setup.
3. On AC models (1-stage cool, 1-stage heat), O/W2 is not
connected. Thermostat can only control 1 stage of heat.
4. Refer to outdoor unit installation instructions for latent kit
requirements.
5. O/W2 can control second-stage heat. Refer to indoor unit
instructions for proper setup.
6. Furnace must control second-stage heat. Refer to furnace
instructions for proper setup.
7. Terminals marked with * are not present on all fan coils.
8. Requires: FK4B fan coil with special 1:2 size ratio heater
package.
Fig. 12—Two-Speed Heat Pump with 2-Stage or
Variable-Speed Furnace
A94225
COOL/HEAT
STAGE 1
RVS COOLING
HEAT STAGE 3
COOL/HEAT
STAGE 2
FAN
24 VAC HOT
R
W/W1
Y/Y2
O/W2
Y1/W2
G
24 VAC COMM.
RVS HEATING
TROUBLE
OUTDOOR
SENSOR
CONNECTION
C
B
L
S1
S2
C
Y2
C
W2
MODEL 2S
THERMOSTAT
TWO-STAGE OR
VARIABLE-SPEED
FURNACE
TWO-SPEED
HEAT PUMP
See note 6
R
Y1
O
R
W3
G
L
W/W1
Y/Y2
W2
6
