1 2 3 4
ZONE 1
1 2 3 4
ZONE 2
1 2 3 4
ZONE 3
1 2 3 4
ZONE 4
1 2 3 4
ZONE 5
1 2 3 4
ZONE 6
PRIORITY
ZONE
2 WIRE ZONE VALVE
(NO END SWITCH)
MUST USE JUMPER
TACO
3 WIRE
ZONE VALVE
1
2
3
JUMPER
3 & 4
MOTOR
END
SWITCH
4 WIRE ZONE VALVE
(POWER OPEN,
SELF CLOSING)
JUMPER
3 & 4
ZVC 406 – 4
SIX ZONE
ZONE VALVE CONTROL
THERMOSTATS
(24VAC)
T STAT 1
VALVE 1
T STAT 2
VALVE 2
T STAT 3
VALVE 3
T STAT 4
VALVE 4
VALVE 5
T STAT 6
VALVE 6
POWER
LED
INDICATORS
T STAT 5
TO: BOILER
AQUASTAT RELAY
ZONE 1 ZONE 2 ZONE 3 ZONE 4 ZONE 5 ZONE 6
ISOLATED
X
X
END SWITCH
THERMOSTATS (24 VAC)
PRIORITY
24 VAC ZONE VALVES
PRIORITY
T
T
ZONE 6
PRIORITY
OFF
ON
NOTE 3:
When a circulator
is used on the priority zone
instead of a zone valve,
jumper 3 and 4 of the
priority zone.
FUSE
5 AMP
R W
INDIRECT
WATER HEATER
AQUASTAT OR
THERMOSTAT
See
NOTE 1
R W
R W
R W
C
C
C
R W C
C
FUSE
5 AMP
R W C
Powered from Transformer
A
Powered from Transformer
B
Powered from Transformer
A
Powered from Transformer
B
24 VAC
FACTORY
INSTALLED
TRANSFORMER
120 VAC
INPUT
WHITE
BLACK
POWER IN
24 VAC
N/O COM N/C
PUMP END
SWITCH
ZONE 6 PUMP
END SWITCH
X
X
DHW
PUMP
SYSTEM PUMP AND BOILER TURN ON WHEN ANY ZONE VALVE OPENS.
DHW PUMP TURNS ON
ONLY
WHEN PRIORITY ZONE CALLS.
SECONDARY PUMP COMES ON WHEN ANY ZONE CALLS
EXCEPT
PRIORITY ZONE.
SYSTEM
PUMP
SECONDARY
PUMP
HOT
NEUTRAL
N
H
NOTE 1:
Terminals
C
are for
optional 24V thermostat
COMMON
connections.
NOTE 2:
Resistor (1K
Ω
,
1
⁄
2
W)
may be needed between
W
and
C
terminals.
See
NOTE 2
24 VAC
FACTORY
INSTALLED
TRANSFORMER
WHITE
BLACK
A
B
Operation/External Diagnostics:
When any thermostat calls for heat,
the appropriate zone valve is energized and the yellow light goes on.
When the zone valve is fully open, the red light goes on and energizes
the end switch relay. The green light should always be on, indicating
that power is connected.
Priority Operation:
When zone 6 is switched to the priority setting and
is actuated, all other zones will stop operation until zone 6 is satisfied.
When zone 6 is not switched to priority, all zones will operate indepen-
dently.
Note:
When a circulator is used on the priority zone instead of a
zone valve, jumper 3 and 4 of the priority zone.
Priority Protection Operation:
When the priority zone calls contin-
uously for more than one hour, power is returned to all the other
zones, allowing each zone to function independently. Once the priori-
ty zone is satisfied, the control's auto-reset is activated and the priority
zone is again allowed to have priority for up to one hour starting from
when it calls next.
Wiring Diagram:
102-397
SUPERSEDES: February 1, 2013
EFFECTIVE: December 20, 2013
Plant ID# 9300-2879
Instruction Sheet
ZVC406 Zone Valve Control
WARNING:
Wiring connections must be made in accordance with all
applicable electrical codes. Use copper wire only. 120 VAC wiring must
have a minimum temperature rating of 75°C. Failure to follow this
instruction can result in personal injury or death and/or property
damage. 12-18 gauge wire recommended for 120 VAC connections,
14-22 gauge wire for thermostat connections, and 14-22 gauge wire for
24 VAC source connections.
Specifications:
PRODUCT
NUMBER
INPUT
MAX 24 VAC
TYPE 1 ENCLOSURE
NUMBER
OF ZONES
VOLTAGE
OUTPUT @ 25°C
WIDTH
HEIGHT
DEPTH
ZVC406-4
6 with Priority
120/60/1 VAC, 3A
24 VA per Zone
12
1
⁄
4
"
8"
3"
40 VA per Transformer
The pump end switches are rated
1
⁄
6
hp, 5 amps at 120 VAC. The main and priority end switch connections
are rated 24 VAC, 1 amp. All thermostat and zone valve connections supply a 24 VAC class 2 output.
Troubleshooting:
• Problem:
Digital thermostats do not work correctly when connected
to a zone valve control.
• Solution:
Some thermostats are a “Power Stealing” type which means
they are powered by the zone control with just 2 wires (
R
&
W
). A resis-
tor may be needed in order to have the thermostat work properly. This
resistor should be placed between the
W
&
C
(
common
) terminals of
the zone control. If the thermostat manufacturer does not supply a
resistor, a 1000 ohm ½ watt resistor has proven to work with most mod-
els and is readily available at electronic supply outlets (e.g. Radio Shack).
If the thermostat is battery powered, then check that the batteries are
fresh and installed correctly.
• Problem:
No heat in a zone or room of building.
• Solution:
LED diagnostic lights will help find a component that is
not working properly. The green LED should always be on, indicat-
ing that power is connected and the fuse is good. When there is a call
for heat, the yellow LED will come on indicating power to the zone
valve. This indicates the thermostat is working correctly. When the
zone valve fully opens and its end switch makes contact, the red LED
will come on, the boiler turns on and a circulator will start if con-
nected to the zone control.
For information on Taco’s Zone Valve Controls
(ZVC) including catalog sheet, instruction sheets,
Visio stencils and our highly praised Zone Controls
Wiring Guide, scan the QR code to the right or go
to our website: http://www.taco-hvac.com.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device
may not cause harmful interference, and (2) this device must accept any interference received, including interference
that may cause undesired operation.
