CALEFFI Z-one ZSR101 Series User manual

Zone Control Relay
ZSR101 Series
NA10331.01
www.caleffi.com
© Copyright 2018Caleffi
Function
The ZSR101 single zone switching relay is operated by low
voltage thermostats. The ZSR101 single zone switching
relay incorporates Power In, Relay 1 and Relay 2 connection
terminals to provide a convenient and cost effective way to
control a circulator and a boiler operating control in a single
zone hydronic heating system. The ZSR101 single zone
switching relay saves hours in installation time and provide a
clean and professional installation.
Code ZSR101 Z-one™Relay switching relay.................................................... single zone
Product range
Materials
Housing plastic: ABS
Front display lights: LED
Electrical Knockouts: (6) 1/2" size
Performance
Power Supply: 120 VAC, 50/60 Hz
Transformer Voltage: 24 VAC
Maximum transformer load: 6 VA
Maximum operating temperature: 110°F (43°C)
Maximum Humidity: 90% non-condensing
Electrical Switch Rating: 10A Max Combined
Replaceable Fuses: Type 2AG, 5A Slow Blow
Approvals: Certified to CSA C22-2 No.24, Conforms to UL Standard 873
Technical specifications
Features
• Compatible with low voltage 2, 3, or 4 wire thermostat
• R, W, C and TT Comm dual labeling at thermostat
terminals
• 120 VAC pump outputs
• High capacity transformer
• Large screw terminal connections
• Simplified wiring with pre-installed jumper
• Heavy duty sealed relay
• Relay 1 and Relay 2 connection terminals
• Fuse protected relays (with spare fuse)
• Easy to read PC board layout
• Compact modern design
• Front LED Lights
• 100% Factory tested with 3 year warranty
• ETL Approved
Certified to C5#C22-2 No.24
Conforms to UL Standard 873
4009064

SAFETY INSTRUCTION
This safety alert symbol will be used in this manual to draw attention to safety
related instructions. When used, the safety alert symbol means ATTENTION!
BECOME ALERT! YOUR SAFETY IS INVOLVED! FAILURE TO FOLLOW
THESE INSTRUCTIONS MAY RESULT IN A SAFETY HAZARD.
CAUTION: All work must be performed by qualified personnel trained in the
proper application, installation, and maintenance of systems in accordance
with all applicable codes and ordinances.
CAUTION: Electrical shock hazard. Disconnect power before installation to
prevent electrical shock or equipment damage. Make sure all connections
are in accordance with the electrical wiring diagram and in accordance with
national and local electrical codes.
WARNING: Avoid electrical noise interference. Do not install near large
conductors, electrical machinery, or welding equipment. Avoid locations
where excessive moisture, corrosive fumes, vibration, or explosive vapors are
present.
Caleffi shall not be liable for damages resulting from stress corrosion, misapplication or misuse of it products.
Dimensions
ZSR101
PWR
ZONE
Single DPDT relay
ZSR101
Single DPDT relay - Input: 120VAC 50/60Hz 10A MAX
Conforms
to UL 873
4009064
CAUTION:RISK OF ELECTRIC SHOCK - DISCONNECT ALL
INPUT POWER PRIOR TO SERVICING
Milwaukee, WI 53208 USA
Code Zones A B C Wgt. (lbs)
ZSR101 1 5 3/8"45/8"25/8"1.1
A
B C
C
WARNING: This product can expose you to chemicals including lead, which is known to the
State of California to cause cancer and birth defects or other reproductive harm. For more
information go to www.P65Warnings.ca.gov.

• Insert flat head screwdriver
into open tab.
• Repeat on opposite side.
Cover removal
• Pull cover straight off.
1 Zone
ZSR101
C
RW
T T COM
L
POWER IN
NC
RELAY #1
NO NC C
RELAY #2
NO NC
TRANSFORMER
PWR
ZONE
When a zone has a demand
from a thermostat (T T or R W)
the relay will close sending 120
VAC to Relay 1 NO terminal
switching ON the pump, Relay
2 closes C to NO dry contact,
signaling the boiler of a heating
demand.
Operating principles
Supply 120 VAC hot to termilan L and 120 VAC neutral to N.
A factory installed jumper from L terminal to the C terminal of
Relay 1 is supplied for simplified pump connection.
1 Zone
ZSR101
C
RW
T T COM
L
POWER IN
NC
RELAY #1
NO NC C
RELAY #2
NO
NC
TRANSFORMER
PWR
ZONE
1 Zone
ZSR101
C
RW
T T COM
L
POWER IN
NC
RELAY #1
NO NC C
RELAY #2
NO NC
TRANSFORMER
PWR
ZONE
R, W, C and T T Comm dual
labeling at thermostat terminals.
Compatible with low voltage 2,
3, or 4 wire thermostats or any
other low voltage devices having
a switching action.

Caleffi North America, Inc.
3883 West Milwaukee Road
Milwaukee, WI 53208
T: 414.238.2360 F: 414.238.2366
CALEFFI
Application Wiring Diagram
Installation
The unit must be only located in dry
interior locations. It is not suitable
for installation in hazardous locations
and should not be placed close to
any electromagnetic fields. Please
pay attention to routing of power
supply cables.
•Remove cover of relay box.
•Identify the four mounting
holes on relay box, mark on
the wall the desired location of
mounting.
•Predrill, anchor, and fasten four
screws for mounting.
•Hang relay box and fasten tight
to desired locations.
•Complete wiring connections
in accordance with terminal
locations.
•Place cover back on relay box.
FUSE FUSE
RWC
TTcom
power
zone
transformer
N LG LG
N LL
RELAY 1
C N/O N/C C N/O N/C
RELAY 2
thermostat
L
N
G
space
heating
demand
variable-speed
pressure-regulated
distribution circulator mod/con boiler
ZSR101
1 Zone
4-16-18

1
1

WIRING GUIDE
4009064
Certified to CSA C22-2 No.24
Conforms to UL Standard 873
The ZSR101 is a versatile single relay control with two outputs for operating a 120 VAC pump with boiler enable, or two 120
VAC devices without boiler enable. Features include rear knock outs for 4x4 junction box mounting, convenient pre-installed
jumper for pump operation, and 10 amp total load rating.
The ZSR Series of controls is for zoning using pumps. Up to 6 zone pumps (model dependent) along with a primary pump
can be operated. Zone priority is selectable with 1-hour time-out feature. Other features include pump exercising, selectable
post purge, and 3 pump ground terminals for simplifi ed wiring.
The ZVR Series of controls is for zoning using zone valves. Up to 6 valves (model dependent), along with a system pump,
secondary pump and zone 1 pump (typically used for DHW priority) can be operated. Zone priority is selectable with 1-hour
time-out feature. System pump and secondary pump status (on/off) during priority is also selectable. Replaceable snap-fi t 40
VA transformer standard for 3 & 4 zone models – expandable to 80 VA with 2nd transformer. 6 zone model has two 40 VA
(80 VA) transformers.
Form 031914 rev.2

3
INDEX
Z-one Relay thermostat connections
Thermostat wiring ........................................................................................................................................................................... 4
Zone valve wiring to ZVR series....................................................................................................................................................... 5
ZSR101 - single zone relay
Product overview ............................................................................................................................................................................ 6
Operation and cover removal ........................................................................................................................................................................7
A1 - Single thermostat ...................................................................................................................................................................................8
A2 - Multiple thermostats...................................................................................................................................................................10
A3 - Single master thermostat, with TRVs, variable speed pump.................................................................................................... 12
ZSR103, ZSR104 & ZSR106 - multi-zone pump relay
Product overview ........................................................................................................................................................................... 14
Circuit board .................................................................................................................................................................................. 15
Cover removal................................................................................................................................................................................ 16
Product details............................................................................................................................................................................... 17
B1 - Mod/Con boiler, hydro separator or buffer tank, zone pumps ................................................................................................. 18
B2 - Traditional boiler, indirect DHW w/ priority, zone pumps .......................................................................................................... 20
B3 - Mod/Con boiler, primary loop, closely spaced tees, zone pumps............................................................................................ 22
B4 - Mod/Con boiler, hydro separator or buffer tank, zone pumps with remote enable................................................................... 24
ZVR103, ZVR104 & ZVR106 - multi-zone valve control
Product overview ........................................................................................................................................................................... 26
Circuit board .................................................................................................................................................................................. 27
Cover removal, Transformer Installation .................................................................................................................................................28
Product details............................................................................................................................................................................... 29
C1 - Mod/Con boiler, hydro separator, zone valves ........................................................................................................................ 30
C2 - Mod/Con boiler, indirect DHW on primary side of hydro sep, zone valves............................................................................... 32
C3 - Mod/Con boiler, indirect DHW on load side of hydro sep, zone valves.................................................................................... 34
C4 - Mod/Con boiler, indirect DHW on primary side of hydro sep, master and slave control........................................................... 36
C5 - Traditional boiler, indirect DHW (no priority) with valve............................................................................................................. 38
C6 - Traditional boiler with reset control, priority indirect DHW with valve........................................................................................ 40
C7 - Mod/Con boiler, hydro separator, zone valve (more than 6), multiple secondary pumps.......................................................... 42
C8 - Mod/Con boiler, indirect DHW on primary side of hydro sep, zone valves with ECM pump enabling....................................... 44
C9 - Mod/Con boiler, hydro separator, zone 1 low temp, 2 - 6 high temp zone valves.................................................................... 46
Caleffi shall not be liable for damages resulting from misapplication or misuse of it products.

4
All Caleffi Z-one controls use the same interface
to connect to thermostats. This interface is
very flexible and allows many different types
of thermostats to be connected to the control
including 2, 3 and 4 wire versions. In addition, any
type of switching device can be used to signal a
heat demand by connecting the R & W (T & T)
terminals together. The terminals are dual labeled
to help simplify wiring.
Z-one Thermostat Connections
L
PUMP 2
N
PRIMARY
PUMP
L
PRIORITY
PUMP 1
N
L
POWER IN
N
GROUNDS
L
PUMP 3
N
TRANSFORMER
LN
L
PUMP 4
NL
PUMP 5
NL
PUMP 6
N
POWER
ZONE1
ZONE2
ZONE3
ZONE4
ZONE5
ZONE6
T-STAT 2
C
RW
T T COM COMMS
DP
ZONE 1
E / S
X X
T-STAT 3
C
RW
T T COM
T-STAT 1
C
RW
T T COM
T-STAT 4
C
RW
T T COM
T-STAT 5
C
RW
T T COM
T-STAT 6
C
RW
T T COM
AUX
6 Zone
ZSR106
MASTER
PRIORITY ON
REMOTE ENABLE ON
EXERCISE ON
POST PURGE ZONE#1 ON
SLAVE
OFF
OFF
OFF
OFF
REMOTE ENABLE
24 - 120 VAC
LN
ON
OFF
STATUS
DURING
PRIORITY
Z-one T-stat interface
Description
R = 24 VAC Supply
W = Heat Call
C = 24 VAC Common
Function
R&W: When connected, signals a heat demand.
R&C: Provides 24 VAC to powered thermostats.
There are a few different types of 2 wire thermostats
including bi-metallic, power stealing and battery
powered. All of these thermostats connect in
the same manner to the Caleffi Z-one series of
controls. Connect R to R and W to W. See below.
2-Wire Thermostats
6 Zone
Z6P
T
HM 2
C
R
W
T
T COM COMMS
DP
DHW
ZR/ZC
X X
THM 3
C
RW
T T COM
THM 1
C
RW
T T COM
L
PUMP 2
N
PRIMARY
PUMP
L
PRIORITY
PUMP 1
N
LPOWER IN
NGROUNDS
L
PUMP 3
N
TRANSFORMER
12/20VA
LN
THM 4
C
RW
T T COM
L
PUMP 4
NL
PUMP 5
NL
PUMP 6
N
THM 5
C
RW
T T COM THM 6
C
RW
T T COM
PWR
ZONE1
ZONE2
ZONE3
ZONE4
ZONE5
ZONE6
DipSwitches
Master Slave
Priority OFF Priority ON
Primary OFF Primary ON
Exercise OFF Exercise ON
Post Purge OFF Post Purge ON
To connect a 4-wire thermostat to the Z-one
series controls, connect R to R, W to W and C
to C. A jumper in the thermostat is also required
between R & Rh as shown below. Similar to a
3-wire thermostat, R & C from the Z-one Control
supply constant 24 VAC to the thermostat.
4-Wire Thermostats
Three wire thermostats get their power from the
control they are connected to. R & C from the
Z-one Control supply 24 VAC to the thermostat at
all times while the W lead signals a heat demand.
3-Wire Thermostats
6 Zone
Z6P
TH
M 2
C
R
W
T
T COM COMMS
DP
DHW
ZR/ZC
X X
THM 3
C
RW
T T COM
THM 1
C
RW
T T COM
L
PUMP 2
N
PRIMARY
PUMP
L
PRIORITY
PUMP 1
N
LPOWER IN
NGROUNDS
L
PUMP 3
N
TRANSFORMER
12/20VA
LN
THM 4
C
RW
T T COM
L
PUMP 4
NL
PUMP 5
NL
PUMP 6
N
THM 5
C
RW
T T COM THM 6
C
RW
T T COM
PWR
ZONE1
ZONE2
ZONE3
ZONE4
ZONE5
ZONE6
DipSwitches
Master Slave
Priority OFF Priority ON
Primary OFF Primary ON
Exercise OFF Exercise ON
Post Purge OFF Post Purge ON
6 Zone
Z6P
TH
M 2
C
R
W
T
T COM COMMS
DP
DHW
ZR/ZC
X X
THM 3
C
RW
T T COM
THM 1
C
RW
T T COM
L
PUMP 2
N
PRIMARY
PUMP
L
PRIORITY
PUMP 1
N
LPOWER IN
NGROUNDS
L
PUMP 3
N
TRANSFORMER
12/20VA
LN
THM 4
C
RW
T T COM
L
PUMP 4
NL
PUMP 5
NL
PUMP 6
N
THM 5
C
RW
T T COM THM 6
C
RW
T T COM
PWR
ZONE1
ZONE2
ZONE3
ZONE4
ZONE5
ZONE6
DipSwitches
Master Slave
Priority OFF Priority ON
Primary OFF Primary ON
Exercise OFF Exercise ON
Post Purge OFF Post Purge ON
6 Zone
Z6P
THM 2
C
RW
T T COM
COMMS
DP
DHW
ZR/ZC
X X THM
3
C
RW
T T
COM
THM 1
C
RW
T T COM
L
PUMP 2
N
PRIMARY
PUMP
L
PRIORITY
PUMP 1
N
LPOWER IN
NGROUNDS
L
PUMP 3
N
TRANSFORMER
12/20VA
LN
THM 4
C
RW
T T COM
L
PUMP 4
NL
PUMP 5
NL
PUMP 6
N
THM 5
C
RW
T T COM THM 6
C
RW
T T COM P
WR
ZONE1
ZONE2
ZONE3
ZONE4
ZONE5
ZONE6
DipSwitches
Master Slave
Priority OFF Priority ON
Primary OFF Primary ON
Exercise OFF Exercise ON
Post Purge OFF Post Purge ON
C R Rh W1
A heat demand can also be initiated by any type
of device that has dry contacts (dry contacts are
a set of contacts that open and close but do not
have any voltage present until supplied from an
outside source). The end switch on a Z-one series
zone valve is an example of a dry contact. Using
a dry contact to connect R to W will initiate a heat
demand.
Dry Contacts
Always refer to the thermostat manufacturer’s instructions.
SAFETY INSTRUCTION
This safety alert symbol will be used in this manual to draw attention to safety
related instructions. When used, the safety alert symbol means ATTENTION!
BECOME ALERT! YOUR SAFETY IS INVOLVED! FAILURE TO FOLLOW THESE
INSTRUCTIONS MAY RESULT IN A SAFETY HAZARD.
CAUTION: All work must be performed by qualified personnel trained in the
proper application, installation, and maintenance of systems in accordance with all
applicable codes and ordinances.
CAUTION: Electrical shock hazard. Disconnect power before installation to prevent
electrical shock or equipment damage. Make sure all connections are in accordance
with the electrical wiring diagram and in accordance with national and local electrical
codes.
CAUTION: Avoid electrical noise interference. Do not install near large conductors,
electrical machinery, or welding equipment. Avoid locations where excessive
moisture, corrosive fumes, vibration, or explosive vapors are present.
Caleffi shall not be liable for damages resulting from misapplication or misuse of it products.
WARNING: NEVER CONNECT R & C DIRECTLY,
this will be a direct short on the 24 VAC supply

5
1
2
3
LPOWER IN
N
POWER
T-SAT
CALL
ZONE 6
L
ZONE #1
PUMP
NL
SEC
PUMPN
STATUS DURING
ZONE #1 DEMAND
ZONE 1
END
SWITCH
MOTOR
ZONE 2
END
SWITCH
MOTOR
ZONE 3
END
SWITCH
MOTOR
ZONE 4
END
SWITCH
MOTOR
ZONE 5
END
SWITCH
MOTOR
ZONE 6
END
SWITCH
MOTOR
L
SYSTEM
PUMP
N
T-STAT 2
C
RW
T T COM COMMS
DP
ZONE 1
E / S
X X
T-STAT 3
C
RW
T T COM
T-STAT 1
C
RW
T T COM T-STAT 4
C
RW
T T COM T-STAT 5
C
RW
T T COM T-STAT 6
C
RW
T T COM
AUX
ON
OFF
ON
OFF
VALVE
OPEN
1
2
3
4
52
2 1 3
4 1 3
White Rogers
1361 Zone Valve 4 wire Zone Valve 2 wire Taco 570
2
Wiring a standard zone valve to Calef Z-one Relay
Since a two wire actuator does not have an end switch for feedback
to the ZVR control, the end switch terminals must have a jumper to
simulate the end switch. If the end switch jumper is not installed, no
demand will be sent to the boiler and the pumps will not turn on.
Wiring a Taco 570 valve to Calef Z-one Relay
When connecting the Taco 570 zone valve to the Caleffi Z-one Relay,
the wiring of this valve can only be done in one way. The left motor
terminal on the ZVR series control must be connected to terminal 2
on the zone valve. The right motor terminal must be connected to
terminal 1 on the zone valve. Lastly, the left end switch terminal
must be connected to terminal 3 on the zone valve. Failure to follow
schematic will lead to damage of product.
Wiring a White Rogers 1361 valve to Calef Z-one Relay
The White Rogers 1361 zone valve requires 24 VAC to terminal 2
at all times, therefor connect to the R terminal of the associated
T-STAT on the ZVR control. The left motor terminal on the ZVR
series control must be connected to terminal 4 on the zone valve.
The right motor terminal must be connected to terminal 1 on the
zone valve. Lastly, the left end switch terminal must be connected
to terminal 3 on the zone valve. The 1361 can not be used on any
zone when the ZVR control is set for priority.
Wiring zone valve to Calef ZVR control

6
Overview
•Compatiblewith2,3and4-wirethermostatsorother
low voltage controllers with switching action
•120VACinput
•Heavyduty,sealed,DPDT,fuseprotectedrelay 
(with spare fuse)
•Twodrycontactoutputs(Relay1andRelay2)for
operating 120 VAC pump with boiler enable or two
devices without boiler enable
•5Acapacityeachrelay-10Atotal
•Rearknock-outsformountingonto4”x4”junctionbox
•Highcapacity6VAtransformer
•Simpliedwiringwithpre-installedjumper
•100%factorytestedwith3yearwarranty
•ETLcertied
See technical brochure 01284 NA for more product
information.
4009064
Certified to CSA C22-2 No.24
Conforms to UL Standard 873
ZSR101 - Single Zone Switching Relay

7
When a zone has a
demand from a thermostat
(TT or R W) the relay will
close sending 120 VAC
to Relay #1 NO terminal
and switching the pump
on, and the C to NO dry
contact on relay #2 closes,
signaling the boiler of a heating demand.
1 Zone
ZSR101
C
RW
T T COM
L
POWER IN
NC
RELAY #1
NO NC C
RELAY #2
NO NC
TRANSFORMER
PWR
ZONE
1 Zone
ZSR101
C
RW
T T COM
L
POWER IN
NCRELAY #1
NO NC CRELAY #2 NO NC
TRANSFORMER
PWR
ZONE
Operating Principles
R, W, C and T T Comm dual labeling at thermostat terminals.
Compatible with low voltage 2, 3, or 4 wire thermostats or any
other low voltage devices having a switching action.
Supply 120 VAC hot to terminal L and 120 VAC neutral to N.
A factory installed jumper from L terminal to the C terminal of
Relay 1 is supplied for simplified pump connection.
Dual labeled T-stat terminals.
Compatible with 2, 3 and 4
wire T-stats.
Replaceable fuses.
6 VA Transformer.
Keyhole mounting
which fits a 4X4
junction box.
Pre-installed jumper. Rear knockout for
4X4 junction box.
If dry contacts are desired from relay #1, remove the factory
installed jumper between L and C.
Cover removal
Hold either the left or the right end
of the box up and at an angle. Use
body for stabilizing relay box. Insert
screwdriver and push tab inward.
Turn box and repeat inserting
screwdriver and pushing tab inward
on opposite side, cover should
release from base.
Slide cover off base.
Mounting: Do not mount to a
surface that exceeds 115°F (45°C).
The unit must be only located in dry
interior locations. Use only copper
conductor supply wire suitable for
at least 105° C. All circuits must
have a common disconnect and
be connected to the same pole of
the disconnect. It is not suitable for
installation in hazardous locations.
120VAC input
power connection

8
T
T
RWC
TTcom
power
zone
transformer
N LL RELAY 1
C N/O N/C C N/O N/C
RELAY 2
CalefÞ!
single zone relay
L
N
A1 - Single thermostat
Hydronic diagram is for illustration purposes only, some components have been removed for simplicity.

9
Sequence of Operation / Settings
• A demand occurs from the thermostat closing
RtoWontheZSR101control.The“ZONE”
LED illuminates.
• The ZSR101 control will power relay #1 and
#2 closing C to NO.
• The NO terminal of relay #1 will send out
120 VAC to your pump. Relay #2 provides
a dry contact closure to signal the boiler of a
demand.
• NOTE: Relay #1 can be used as a dry contact
as well by removing the factory installed
jumper between L and C.
• When the thermostat demand is satisfied R to
Wwillopenandthe“ZONE”LEDwillturnoff.
• The control will remove power from relays #1
and #2 opening C to NO. This will drop 120
VAC to your pump and terminate the demand
to your boiler.
Description of terminals
= Ground
N = Neutral (Common leg of 120 VAC)
L = Line (live leg of 120 VAC)
C = Common terminal
NO = Normally Open terminal
NC = Normally Closed terminal
Note: There is a factory installed jumper between the 120
VAC line (L) and the common terminal of relay #1 (C).
Thermostat terminals
R = 24 VAC
W = Heat call
C = Common of 24 VAC
WARNING: NEVER CONNECT R & C DIRECTLY,
this will be a direct short on the 24 VAC supply

10
RWC
TTcom
power
zone
transformer
N LL RELAY 1
C N/O N/C C N/O N/C
RELAY 2
CalefÞ!
single zone relay
4-wire zone valve 4-wire zone valve 4-wire zone valve
R W
24 VAC
T
T
RWRW
End switch wires
L
N
A2 - Multiple thermostats
Hydronic diagram is for illustration purposes only and could be missing system components.

11
Sequence of Operation / Settings
• A demand occurs from one of the thermostats
which sends power (from a separately sourced
transformer) to the corresponding zone valve.
• When the zone valve opens the end switch
will close R to W on the ZSR101 control. The
“ZONE”LEDilluminates.
• The ZSR101 control will power relay #1 and
#2 closing C to NO.
• The NO terminal of relay #1 will send out
120 VAC to your pump. Relay #2 provides
a dry contact closure to signal the boiler of a
demand.
• NOTE: Relay #1 can be used as a dry contact
as well by removing the factory installed
jumper between L and C.
• When all the thermostat demands are satisfied
the zone valves will close and the end switch
willopen Rto W.The“ZONE” LEDwillturn
off.
• The control will remove power from relays #1
and #2 opening C to NO. This will drop 120
VAC to your pump and terminate the demand
to your boiler.
WARNING: NEVER CONNECT R & C DIRECTLY,
this will be a direct short on the 24 VAC supply
Description of terminals
= Ground
N = Neutral (Common leg of 120 VAC)
L = Line (live leg of 120 VAC)
C = Common terminal
NO = Normally Open terminal
NC = Normally Closed terminal
Note: There is a factory installed jumper between the 120
VAC line (L) and the common terminal of relay #1 (C).
Thermostat terminals
R = 24 VAC
W = Heat call
C = Common of 24 VAC

12
buer tank
thermostatic
radiator valves
(TRV) on each
radiator
TRV
TRV
TRV
TRV
TRV TRV
RWC
TTcom
power
zone
transformer
NLLRELAY 1
C N/ON/C C N/ON/C
RELAY 2
ZSR101
T
T
L
N
A3 - Single master thermostat, panel radiators with TRVs, variable speed pump
Hydronic diagram is for illustration purposes only, some components have been removed for simplicity.

13
Sequence of Operation / Settings
• A demand occurs from the thermostat closing
RtoWontheZSR101control.The“ZONE”
LED illuminates.
• The ZSR101 control will power relay #1 and
#2 closing C to NO.
• The NO terminal of relay #1 will send out
120 VAC to your pumps. Relay #2 provides
a dry contact closure to signal the boiler of a
demand.
• NOTE: Relay #1 can be used as a dry contact
as well by removing the factory installed
jumper between L and C.
• When the thermostat demand is satisfied R to
Wwillopenandthe“ZONE”LEDwillturnoff.
• The control will remove power from relays #1
and #2 opening C to NO. This will drop 120
VAC to your pumps and terminate the demand
to your boiler.
• NOTE: In this application, the single thermostat
will be set to a slightly higher temperature
than the desired room temperatures. The
room temperatures will then be controlled by
each individual thermostatic radiator valve
by adjusting the flow through the radiator
making this a fitting application for a variable
speed (ECM) pump (between the buffer tank
and radiators). When the temperature drops
below the set point of the thermostat the
boiler will maintain the buffer tank at its target
temperature. Ideally, the boiler will operate on
an outdoor reset curve to maximize efficiency
and use a system temperature sensor located
in the upper portion of the buffer tank.
WARNING: NEVER CONNECT R & C DIRECTLY,
this will be a direct short on the 24 VAC supply
Description of terminals
= Ground
N = Neutral (Common leg of 120 VAC)
L = Line (live leg of 120 VAC)
C = Common terminal
NO = Normally Open terminal
NC = Normally Closed terminal
Note: There is a factory installed jumper between the 120
VAC line (L) and the common terminal of relay #1 (C).
Thermostat terminals
R = 24 VAC
W = Heat call
C = Common of 24 VAC

14
ZSR10X - Multi-Zone Pump Control
Overview
• Compatible with low voltage 2, 3, or 4 wire
thermostats
• R, W, C and TT Comm dual labeling at thermostat
terminals
• Z-oneLink unlimited zone expansion
• 120 VAC pump outputs
• Selectable priority with 1 hour time-out feature
• Selectable post purge and exercise
• Dry contacts (X X , AUX, ZONE 1 E/S) capable of
switching line voltage
• High capacity transformer
• Large terminal connections
• Simplified wiring with extra ground terminals
• Heavy duty sealed relays
• Fuse protected (with spare fuse)
• Front LED lights
• 100%Factorytestedwith3yearwarranty
• ETL approved
See technical brochure 01286 NA for more product
information.
4009064
Certified to CSA C22-2 No.24
Conforms to UL Standard 873

15
120 VAC primary
pump output.
Multiple ground
connections for
easy wiring.
Replaceable
fuses (2 extra
included under
cover).
3 wire
communications to
expansion board. Power ON LED.
Dual labeled
T-stat terminals.
Compatible with
2, 3 and 4 wire
T-stats. Selectable DIP
switches.
LED for each
zone.
120 VAC zone
pump outputs.
120 VAC input
power connection
ZONE1 /ES closes
only during a
demand from zone 1.
Rated for
120 VAC
2 Amps.
X X closes on a
demand for heat
from any zone.
Rated for
120 VAC
2 Amps.
AUX closes on a
demand for heat
from any zone.
Rated for
120 VAC
2 Amps.

16
Cover removal
Hold either the left or the right end
of the box up and at an angle. Use
body for stabilizing relay box.
Insert screwdriver and push tab
inward, cover should release from
base.
Roll cover off base.
Mounting: Do not mount to a surface that exceeds 115°F (45°C). The unit must
be only located in dry interior locations. Use only copper conductor supply wire
suitable for at least 105° C. All circuits must have a common disconnect and be
connected to the same pole of the disconnect. It is not suitable for installation
in hazardous locations.