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6
A qualified HVAC technician
should perform this step to
ensure proper termination.
1. Make sure the HVAC
system power is off.
2. The Thermostat
Installation Instructions
show wiring diagrams for
several different HVAC
equipment types. Use
DIAGRAMS 1 & 2 as a
reference only. Use color
coding where possible.
RC
RH
G
R.V.-Cool (O)R.V.-Cool (O)
W2
C
RSC
RSA
RSB
RSR
R
REF
Y2
B-
B+
A+
A-
FAN
RELAY
2ND
STAGE
HEAT
1ST
STAGE
HEAT
R
MULTI-STAGE FURNACE
C
G
W1
Y1
W2
Y2
1ST STAGE
COOL
2ND STAGE
COOL
L1
L2
120
VAC
24
VAC
1ST
STG
COOL
2ND
STG
COOL
MULTI-STAGE A/C
Y1
C
Y2
CAUTION!
ENSURE HVAC SYSTEM POWER
IS OFF BEFORE WIRING
USE 18-20 GA. THERMOSTAT CABLE. NUMBER OF CONDUCTORS
REQUIRED DEPENDS ON THE HVAC SYSTEM BEING CONTROLLED
REFER TO THE THERMOSTAT INSTALLATION SHEET FOR
INTERNAL SCHEMATIC, THERMOSTAT CHECK-OUT
PROCEDURES AND OTHER HVAC WIRING DETAILS
R.V.-Heat (B)R.V.-Heat (B)
DEH Y1
HUM W1
RC
RH
G
W2
C
RSC
RSA
RSB
RSR
R
REF
Y2
B-
B+
A+
A-
CAUTION!
ENSURE HVAC SYSTEM POWER
IS OFF BEFORE WIRING
USE 18-20 GA. THERMOSTAT CABLE. NUMBER
OF CONDUCTORS REQUIRED DEPENDS ON THE
HVAC SYSTEM BEING CONTROLLED
REFER TO THE THERMOSTAT INSTALLATION
SHEET FOR INTERNAL SCHEMATIC, THERMOSTAT
CHECK-OUT PROCEDURES AND OTHER HVAC
WIRING DETAILS
FAN
RELAY
2ND
STAGE
AUX.
HEAT
1ST
STAGE
AUX.
HEAT
R
INDOOR BLOWER/HEAT UNIT
C
G
W1
W2
L1
L2
120
VAC
24
VAC
1ST
STG
COMP.
REV
VALVE
COOL
REV
VALVE
HEAT
DEFROST
SERVICE
OUTDOOR HEAT PUMP UNIT
2ND
STG
COMP.
Y1
O
B
W1
L
C
R
Y2
DEH Y1
HUM W1
R.V.-Cool (O)R.V.-Cool (O)
R.V.-Heat (B)R.V.-Heat (B)
DO NOT TURN ON
THE HVAC SYSTEM
POWER YET!
CONNECT THE CONTROL WIRES TO THE HVAC/ZONE SYSTEM AND THERMOSTATS
Step 5
DIAGRAM 2 – Typical Heat Pump Wiring Schematic
DIAGRAM 1 – Typical Heating / Cool Wiring Schematic