Wiring Guide
WIRING DIAGRAMS – THERMOSTAT & SUMMER/WINTER SWITCH
13 6-461.1
Single Stage Thermostat & Summer/Winter Switch Wiring
Y
G
R
C
W
W
G
1-STAGE LOW VOLTAGE ROOM
STAT WITH SUB-BASE SWITCHING
(BY OTHERS)
R C
W
1-STAGE LOW VOLTAGE ROOM
STAT WITH NO SWITCHING
(BY OTHERS)
R C
TERMINAL STRIP
ON UNIT HEATER
SUMMER/WINTER
SWITCH
(BY OTHERS)
WINTER
SUMMER
FAN OPERATION:
SUMMER - CONTINUOUS FAN
WINTER - INTERMITTENT FAN ON A CALL FOR HEAT
FAN OPERATION (BASED ON FAN SUB-BASE SWITCH):
SWITCH = ON - CONTINUOUS
SWITCH = AUTO - INTERMITTENT ON A CALL FOR HEAT
TERMINAL STRIP
ON UNIT HEATER
1-STAGE ROOM STAT
W
ITH SUB-BASE FAN SWITCH
SUMMER/WINTER SWITCH & 1-STAGE ROOM STAT
W
ITHOUT SUB-BASE FAN SWITCH
Y
G
R
C
W
W
G
1-STAGE LOW VOLTAGE ROOM
STAT WITH SUB-BASE SWITCHING
(BY OTHERS)
R C
FAN OPERATION (BASED ON FAN SUB-BASE SWITCH):
SWITCH = ON - CONTINUOUS
SWITCH = AUTO - INTERMITTENT ON A CALL FOR HEAT
TERMINAL BOARD
ON UNIT HEATER
T2
FG
CVT1
MODELS HD/HDB, HDS/HDC, AND PTS/BTS MODEL PTC
W
1-STAGE LOW VOLTAGE ROOM
STAT WITH NO SWITCHING
(BY OTHERS)
R C
TERMINAL BOARD
ON UNIT HEATER
SUMMER/WINTER
SWITCH
(BY OTHERS)
FAN OPERATION:
SUMMER - CONTINUOUS FAN
WINTER - INTERMITTENT FAN ON A CALL FOR HEAT
T2
FG
CVT1
WINTER
SUMMER
Two Stage Thermostat & Summer/Winter Switch Wiring
G
W1
C
R
W2
W2
G
W1
2-STAGE LOW VOLTAGE ROOM
STAT WITH SUB-BASE SWITCHING
(BY OTHERS)
R C
G
W1
C
R
W2
W2
W1
NOTE:
GENERIC ROOM STAT TERMINALS SHOWN. ACTUAL STAT MAY USE DIFFERENT TERMINALS AND/OR
WIRING. PLEASE CONSULT WIRING INSTRUCTIONS FOR STAT FOR PROPER WIRING.
2-STAGE LOW VOLTAGE ROOM
STAT WITH NO SWITCHING
(BY OTHERS)
R
C
TERMINAL STRIP
ON UNIT HEATER
SUMMER/WINTER
SWITCH
(BY OTHERS)
FAN OPERATION:
SUMMER - CONTINUOUS FAN
WINTER - INTERMITTENT FAN ON A CALL FOR HEAT
FAN OPERATION (BASED ON FAN SUB-BASE SWITCH):
SWITCH = ON - CONTINUOUS
SWITCH = AUTO - INTERMITTENT ON A CALL FOR HEAT
TERMINAL STRIP
ON UNIT HEATER
2-STAGE ROOM STAT
W
ITH SUB-BASE FAN SWITCH
SUMMER/WINTER SWITCH & 2-STAGE ROOM STAT
W
ITHOUT SUB-BASE FAN SWITCH
MODELS HD/HDB, HDS/HDC, AND PTS/BTS
WINTER
SUMMER
Notes on Thermostat and Summer/Winter Switch
Wiring:
Units are equipped as standard with a controller that
activates the unit fan in either of the following ways:
• On a call for heat (thermostat closure between R & W
terminals (W1 for 2-stage units) on the unit heater
terminal strip (T1 & T2 on the external terminal board
for model PTC units). The control automatically
recognizes a call for heat as requiring fan operation.
• With switch closure between R & G terminals on the
unit heater terminal strip (T1 & G on the external
terminal board for model PTC units). The control
recognizes this as an override to the fan control based
on a call for heat and starts the fan.
The diagrams on this page are arranged as follows:
1. Single stage thermostat with a Fan On/Auto switch for
fan control.
2. Single stage thermostat without a Fan On/Auto switch
and a Summer/Winter switch for fan control.
3. Two stage thermostat with a Fan On/Auto switch for
fan control.
4. Two stage thermostat without a Fan On/Auto switch
and a Summer/Winter switch for fan control.
Note: A Summer/Winter switch used on these models does
NOT require a control relay as was required on previous
models.