A95218
Fig. 5—Two-Stage or Variable-Speed Furnace with
2-Speed Heat Pump
Y/Y2
W/W1
R
24 VAC HOT
FAN
FURNACE
COMPRESSOR
HI
RVS COOLING
COMPRESSOR
LO
DUAL FUEL
THERMOSTAT
TWO-SPEED
HEAT PUMP
24 VAC COM
RVS HEATING
RVS SENSING
OUTDOOR
SENSOR
CONNECTION
S2
S1
L
B
G
R
R
Y2
G
C
C
C
O/W2
Y1/W2
TWO-STAGE OR
VARIABLE SPEED
FURNACE
W2
O
SEE NOTES 1 AND 2
W/W1
Y/Y2
O
Y1
W2
Y1
W3
OUTDOOR
TEMPERATURE
SENSOR
WIRING DIAGRAM NOTES:
1. Underlined letter on dual terminal indicates its usage.
For Example: O/W2 means O, O/W2 means W2.
Outdoor Temperature Sensor must be attached in all dual
fuel installations.
Jumper wire between O/W2 and L thermostat terminals
MUST be present.
2. Y1 and O connections to 2-stage furnaces MAY NOT
EXIST, or may be only a wire rather than a screw terminal.
—6—
