Wiring Guide
SR501-OR-4 – One Zone Switching Relay with Outdoor Reset
ONE ZONE INSTALLATION
W/O INDIRECT DHW
ONE ZONE
SWITCHING RELAY
WITH OUTDOOR RESET
SR 501-OR-4
LED
INDICATORS
POWER
TSTAT
DHW
OVERRIDE
BOILER
RELAY
NH
INPUT
120 VAC
ZONE 1
120 VAC
NH
6
AMP
X
R
BOILER TSTAT
W
CR
W
DHW
OUTDOOR
SENSOR
SUPPLY
SENSOR
X
DESIGN OUTDOOR
TEMPERATURE
FOR 180°F SUPPLY
TEMPERATURE
OFF
-30
-20
0
-10 10
20
40
30
ON
SW1
OFF
SYSTEM
CIRCULATOR
(OPTIONAL)
N
H
POWER
INPUT
(120 VAC)
24 VAC
THERMOSTAT
BOILER
CONTROL
OUTDOOR
SENSOR
BOILER
SUPPLY
SENSOR
POT1
ZONE VALVE INSTALLATION
W/O ZONE CONTROL, W/O INDIRECT DHW
ONE ZONE
SWITCHING RELAY
WITH OUTDOOR RESET
SR 501-OR-4
LED
INDICATORS
POWER
TSTAT
DHW
OVERRIDE
BOILER
RELAY
NH
INPUT
120 VAC
ZONE 1
120 VAC
NH
6
AMP
X
R
BOILER TSTAT
W
CR
W
DHW
OUTDOOR
SENSOR
SUPPLY
SENSOR
X
DESIGN OUTDOOR
TEMPERATURE
FOR 180°F SUPPLY
TEMPERATURE
OFF
-30
-20
0
-10 10
20
40
30
ON
SW1
OFF
SYSTEM
CIRCULATOR
(OPTIONAL)
N
H
POWER
INPUT
(120 VAC)
BOILER
CONTROL
OUTDOOR
SENSOR
BOILER
SUPPLY
SENSOR
POT1
ZONE VALVE
END SWITCH(S)
THERMOSTATS
(24VAC)
TRANSFORMER
24 VAC
120 VAC
INPUT
MULTI-ZONE INSTALLATION
WITH ZONE CONTROL, W/O INDIRECT DHW
ONE ZONE
SWITCHING RELAY
WITH OUTDOOR RESET
SR 501-OR-4
LED
INDICATORS
POWER
TSTAT
DHW
OVERRIDE
BOILER
RELAY
NH
INPUT
120 VAC
ZONE 1
120 VAC
NH
6
AMP
X
R
BOILER TSTAT
W
CR
W
DHW
OUTDOOR
SENSOR
SUPPLY
SENSOR
X
DESIGN OUTDOOR
TEMPERATURE
FOR 180°F SUPPLY
TEMPERATURE
OFF
-30
-20
0
-10 10
20
40
30
ON
SW1
OFF
SYSTEM
CIRCULATOR
(OPTIONAL)
N
H
POWER
INPUT
(120 VAC)
BOILER
CONTROL
OUTDOOR
SENSOR
BOILER
SUPPLY
SENSOR
POT1
1234
ZONE 1
1234
ZONE 2
1234
ZONE 3
EXISTING
ZONE VALVE CONTROL
POWER IN
24 VAC
N/O
COM
N/C
PUMP END
SWITCH
FUSE
5 AMP
ZONE 3 PUMP
END SWITCH
THERMOSTATS
(24VAC)
T STAT 1
VALVE 1
T STAT 2
VALVE 2
T STAT 3
VALVE 3
POWER
LED
INDICATORS
ZONE 1 ZONE 2 ZONE 3
ISOLATED
XX
RW
RW RW
END SWITCH THERMOSTATS
PRIORITY
24 VAC ZONE VALVES PRIORITY
XX
ZONE 3
PRIORITY
OFF
ON
CCC
2 WIRE ZONE VALVE
(NO END SWITCH)
MUST USE JUMPER
TACO 3 WIRE
ZONE VALVE
1
2
3
JUMPER
3 & 4
TACO 3 WIRE
ZONE VALVE
1
2
3
MULTI-ZONE INSTALLATION
WITH ZONE CONTROL, WITH INDIRECT DHW
ONE ZONE
SWITCHING RELAY
WITH OUTDOOR RESET
SR 501-OR-4
LED
INDICATORS
POWER
TSTAT
DHW
OVERRIDE
BOILER
RELAY
NH
INPUT
120 VAC
ZONE 1
120 VAC
NH
6
AMP
X
R
BOILER TSTAT
W
CR
W
DHW
OUTDOOR
SENSOR
SUPPLY
SENSOR
X
DESIGN OUTDOOR
TEMPERATURE
FOR 180°F SUPPLY
TEMPERATURE
OFF
-30
-20
0
-10 10
20
40
30
ON
SW1
OFF
SYSTEM
CIRCULATOR
(OPTIONAL)
N
H
POWER
INPUT
(120 VAC)
BOILER
CONTROL
OUTDOOR
SENSOR
BOILER
SUPPLY
SENSOR
POT1
1234
ZONE 1
1234
ZONE 2
1234
ZONE 3
EXISTING
ZONE VALVE CONTROL
POWER IN
24 VAC
N/O
COM
N/C
PUMP END
SWITCH
FUSE
5 AMP
ZONE 3 PUMP
END SWITCH
THERMOSTATS
(24VAC)
T STAT 1
VALVE 1
T STAT 2
VALVE 2
T STAT 3
VALVE 3
POWER
LED
INDICATORS
ZONE 1 ZONE 2 ZONE 3
ISOLATED
XX
RW
RW RW
END SWITCH THERMOSTATS
PRIORITY
24 VAC ZONE VALVES PRIORITY
XX
ZONE 3
PRIORITY
OFF
ON
CCC
2 WIRE ZONE VALVE
(NO END SWITCH)
MUST USE JUMPER
TACO 3 WIRE
ZONE VALVE
1
2
3
JUMPER
3 & 4
TACO 3 WIRE
ZONE VALVE
1
2
3
DHW
AQUASTAT
A
4