Installation Guide
63
H
N
ComSup Boil Out Heat
Dem
Com Com
Sys
Ret
Power
Cord
Radiant Manifold - Supply
Radiant Manifold - Return
X - Pump Block Connected to Zone Valve Control
Output to
System
Exp
Tank
Pressure
Relief
Supply
Sensor
XPB
Back of Control
Off-Enable On-Control
Boiler Operation
Pump
Outdoor
Sensor
Boiler
HEAT
SOURCE
Input from
Heat Source
H
N
ComSup BoilOut Heat
Dem
Com Com
Sys
Ret
Power
Input
Power
Cord
Input from
Heat Source
Output to
System
Supply
Sensor
Return
Sensor
Exp
Tank
Pressure
Relief
X - Pump Block Connected to 2 SR502/503 Switching Relays
XPB
Back of Control
Off-Enable On-Control
Boiler Operation
Pump
Outdoor
Sensor
Boiler
H
N
1 2 3 4
ZONE 1
1 2 3 4
ZONE 2
1 2 3 4
ZONE 3
1 2 3 4
ZONE 4
PRIORITY
ZONE
JUMPER
3 & 4
ZVC 404 – 4
FOUR ZONE
ZONE VALVE CONTROL
FACTORY
INSTALLED
TRANSFORMER
120 VAC
INPUT
WHITE
BLACK
POWER IN
24 VAC
TO
CIRCULATOR
DRY
CONTACTS
N/O
COM
N/C
PUMP END
SWITCH
FUSE
5 AMP
ZONE 4 PUMP
END SWITCH
T STAT 1
VALVE 1
T STAT 2
VALVE 2
T STAT 3
VALVE 3
T STAT 4
VALVE 4
POWER
LED
INDICATORS
ZONE 1 ZONE 2 ZONE 3 ZONE 4
ISOLATED
X X
END SWITCH THERMOSTATS (24 VAC) PRIORITY
24 VAC ZONE VALVES
PRIORITY
X X
ZONE 4
PRIORITY
OFF
ON
NOTE 2: When a circulator
is used on the priority zone
instead of a zone valve,
jumper 3 and 4 of the
priority zone.
THERMOSTATS (24VAC)
R W R W R W
C C C
See NOTE 1
R W
C
NOTE 1: Terminals C are for
optional 24V thermostat
COMMON connections.
H
N
PRIORITY
OFF
T T T
TT
THERMOSTATS
TWO ZONE SWITCHING RELAY
CIRCULATORS
ZC
INPUT
120 VAC
ZONE 1
ZONE 2
PRIORITY
ZONE1
ZONE2
PRIORITY
SR 502-4
FUSE
6 AMP
FUSE
6 AMP
FUSE
6 AMP
X X R W R W
ISOLATED
END
SWITCH
THERMOSTATS
120 VAC
ZR
H H N H N H N H
ZONE 2
POWER
ZONE 1
LED
INDICATORS
ZONE 2
PRIORITY
OFF
ON
24 VAC
COM
PRIORITY
OFF
Power
Input
H
N
TT
THERMOSTATS
TWO ZONE SWITCHING RELAY
CIRCULATORS
ZC
INPUT
120 VAC
ZONE 1
ZONE 2
PRIORITY
ZONE1
ZONE2
PRIORITY
SR 502-4
FUSE
6 AMP
FUSE
6 AMP
FUSE
6 AMP
X X R W R W
ISOLATED
END
SWITCH
THERMOSTATS
120 VAC
ZR
H H N H N H N H
ZONE 2
POWER
ZONE 1
LED
INDICATORS
ZONE 2
PRIORITY
OFF
ON
24 VAC
COM
PRIORITY
OFF
FOR ADDITIONAL WIRING DIAGRAMS, PLEASE SEE www.taco-hvac.com/wiringwizard










