4
Example circuit diagrams for some typical installations are shown below. These diagrams are
schematic and should be used as a guide only.
Please ensure that all installations comply with the current IEE regulations.
For reasons of space and clarity not every system has been included and the diagrams have been
simplified (for example some earth connections have been omitted)
Other control components shown in the diagrams i.e. valves, room stats etc are general
representations only. However the wiring detail can be applied to the corresponding models of most
manufacturers, e.g. Horstmann, Honeywell, Danfoss Randall, ACL Drayton etc.
Cylinder and Room Thermostat Key:
C = Common CALL = Call for heat or break on rise SAT = Satisfied on rise N = Neutral
Typical wiring diagrams
5
4
Example circuit diagrams for some
typical installations are shown below.
These diagrams are schematic and
should be used as a guide only.
Please ensure that all installations
comply with the current IEE
regulations.
For reasons of space and clarity not
every system has been included and
the diagrams have been simplified
(for example some earth connections
have been omitted)
Other control components shown
in the diagrams i.e. valves, room
stats etc are general representations
only. However the wiring detail can
be applied to the corresponding
models of most manufacturers, e.g.
Horstmann, Honeywell, Danfoss
Randall, ACL Drayton etc.
Cylinder and Room Thermostat
Key:
C = Common CALL = Call for heat
or break on rise
SAT = Satisfied on rise
N = Neutral
Typical wiring diagrams
N
L
1
2
3
4
5
6
E
E
N
L
N
L
MAINS
SUPPLY
COMBINATION BOILER TERMINALS
FOR PRECISE TERMINAL
CONNECTION INFORMATION
PLEASE REFER TO BOILER
MANUFACTURER INSTRUCTIONS
TERMINALS L - 5
SHOULD NOT
BE LINKED
REMOVE
LINK IF
FITTED
ROOM
STAT
CALL
SAT
N
C
BOILER LIVE OUT
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
CYL
STAT
CALL
CALL
N
N
L
L
BOILER
PUMP
SAT
SAT
N
C
C
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
ZONE
VALVE
N
C
CYL
STAT
CALL
CALL
SAT
SAT
C
N
L
PUMP &
BOILER
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
N
N
L
L
BOILER
PUMP
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
N
N
L
L
BOILER
PUMP
CYL
STAT
CALL
SAT
C
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
CYL
STAT
CALL
SAT
C
N
L
PUMP &
BOILER
ZONE
VALVE
ZONE
VALVE
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
BR
BL
W
GR
0
CALL
SAT
C
N
N
L
L
BOILER
PUMP
ROOM
STAT
CYL
STAT
ZONE VALVE
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
CALL
SAT
C
W
BL
0
GR
MID POSITION
VALVE
N
L
PUMP &
BOILER
FROST
STAT
IF
FITTED
C
CALL
ROOM
STAT
CYL
STAT
425 Coronet controlling typical combination boiler
installation via room thermostat.
425 Tiara controlling fully pumped system using two
motorised 2 port valves with auxiliary switches via
room stat and cylinder stat.
425 Diadem/Tiara controlling gravity hot water with
pumped heating via room stat and cylinder stat.
425 Coronet controlling gravity hot water with
pumped heating via room stat and cylinder stat.
Fully pumped system using roomstat and two (2 port)
spring return zone valve with auxiliary switches.
425 Diadem/Tiara controlling gravity hot water with
pumped heating via room stat and cylinder stat.
425 Coronet controlling fully pumped system via room
stat,cylinder stat and using a 2 port spring return valve
with auxiliary switch on heating circuit.
425 Tiara controlling fully pumped system using a mid
position valve via room stat and cylinder stat.
425 Diadem/Tiara controlling gravity hot water with
pumped heating using a 2 port spring return valve with
changeover auxiliary switch on the hot water circuit.
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
CALL
SAT
C
FROST
STAT
IF
FITTED
C
CALL
ROOM
STAT
CYL
STAT
N
L
PUMP &
BOILER
ZONE
VALVE
ZONE
VALVE
5
4
Example circuit diagrams for some
typical installations are shown below.
These diagrams are schematic and
should be used as a guide only.
Please ensure that all installations
comply with the current IEE
regulations.
For reasons of space and clarity not
every system has been included and
the diagrams have been simplified
(for example some earth connections
have been omitted)
Other control components shown
in the diagrams i.e. valves, room
stats etc are general representations
only. However the wiring detail can
be applied to the corresponding
models of most manufacturers, e.g.
Horstmann, Honeywell, Danfoss
Randall, ACL Drayton etc.
Cylinder and Room Thermostat
Key:
C = Common CALL = Call for heat
or break on rise
SAT = Satisfied on rise
N = Neutral
Typical wiring diagrams
N
L
1
2
3
4
5
6
E
E
N
L
N
L
MAINS
SUPPLY
COMBINATION BOILER TERMINALS
FOR PRECISE TERMINAL
CONNECTION INFORMATION
PLEASE REFER TO BOILER
MANUFACTURER INSTRUCTIONS
TERMINALS L - 5
SHOULD NOT
BE LINKED
REMOVE
LINK IF
FITTED
ROOM
STAT
CALL
SAT
N
C
BOILER LIVE OUT
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
CYL
STAT
CALL
CALL
N
N
L
L
BOILER
PUMP
SAT
SAT
N
C
C
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
ZONE
VALVE
N
C
CYL
STAT
CALL
CALL
SAT
SAT
C
N
L
PUMP &
BOILER
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
N
N
L
L
BOILER
PUMP
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
N
N
L
L
BOILER
PUMP
CYL
STAT
CALL
SAT
C
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
CYL
STAT
CALL
SAT
C
N
L
PUMP &
BOILER
ZONE
VALVE
ZONE
VALVE
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
BR
BL
W
GR
0
CALL
SAT
C
N
N
L
L
BOILER
PUMP
ROOM
STAT
CYL
STAT
ZONE VALVE
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
CALL
SAT
C
W
BL
0
GR
MID POSITION
VALVE
N
L
PUMP &
BOILER
FROST
STAT
IF
FITTED
C
CALL
ROOM
STAT
CYL
STAT
425 Coronet controlling typical combination boiler
installation via room thermostat.
425 Tiara controlling fully pumped system using two
motorised 2 port valves with auxiliary switches via
room stat and cylinder stat.
425 Diadem/Tiara controlling gravity hot water with
pumped heating via room stat
425 Coronet controlling gravity hot water with
pumped heating via room stat and cylinder stat.
425 Tiara controlling fully pumped system using room
stat and two (2 port) spring return zone valve with
auxiliary switches
425 Diadem/Tiara controlling gravity hot water with
pumped heating via room stat and cylinder stat.
425 Coronet controlling fully pumped system via room
stat,cylinder stat and using a 2 port spring return valve
with auxiliary switch on heating circuit.
425 Tiara controlling fully pumped system using a mid
position valve via room stat and cylinder stat.
425 Diadem/Tiara controlling gravity hot water with
pumped heating using a 2 port spring return valve with
changeover auxiliary switch on the hot water circuit.
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
CALL
SAT
C
FROST
STAT
IF
FITTED
C
CALL
ROOM
STAT
CYL
STAT
N
L
PUMP &
BOILER
ZONE
VALVE
ZONE
VALVE
5
4
Example circuit diagrams for some
typical installations are shown below.
These diagrams are schematic and
should be used as a guide only.
Please ensure that all installations
comply with the current IEE
regulations.
For reasons of space and clarity not
every system has been included and
the diagrams have been simplified
(for example some earth connections
have been omitted)
Other control components shown
in the diagrams i.e. valves, room
stats etc are general representations
only. However the wiring detail can
be applied to the corresponding
models of most manufacturers, e.g.
Horstmann, Honeywell, Danfoss
Randall, ACL Drayton etc.
Cylinder and Room Thermostat
Key:
C = Common CALL = Call for heat
or break on rise
SAT = Satisfied on rise
N = Neutral
Typical wiring diagrams
N
L
1
2
3
4
5
6
E
E
N
L
N
L
MAINS
SUPPLY
COMBINATION BOILER TERMINALS
FOR PRECISE TERMINAL
CONNECTION INFORMATION
PLEASE REFER TO BOILER
MANUFACTURER INSTRUCTIONS
TERMINALS L - 5
SHOULD NOT
BE LINKED
REMOVE
LINK IF
FITTED
ROOM
STAT
CALL
SAT
N
C
BOILER LIVE OUT
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
CYL
STAT
CALL
CALL
N
N
L
L
BOILER
PUMP
SAT
SAT
N
C
C
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
ZONE
VALVE
N
C
CYL
STAT
CALL
CALL
SAT
SAT
C
N
L
PUMP &
BOILER
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
N
N
L
L
BOILER
PUMP
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
N
N
L
L
BOILER
PUMP
CYL
STAT
CALL
SAT
C
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
ROOM
STAT
N
C
CALL
SAT
CYL
STAT
CALL
SAT
C
N
L
PUMP &
BOILER
ZONE
VALVE
ZONE
VALVE
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
BR
BL
W
GR
0
CALL
SAT
C
N
N
L
L
BOILER
PUMP
ROOM
STAT
CYL
STAT
ZONE VALVE
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
CALL
SAT
C
W
BL
0
GR
MID POSITION
VALVE
N
L
PUMP &
BOILER
FROST
STAT
IF
FITTED
C
CALL
ROOM
STAT
CYL
STAT
425 Coronet controlling typical combination boiler
installation via room thermostat.
425 Tiara controlling fully pumped system using two
motorised 2 port valves with auxiliary switches via
room stat and cylinder stat.
425 Diadem/Tiara controlling gravity hot water with
pumped heating via room stat
425 Coronet controlling gravity hot water with
pumped heating via room stat and cylinder stat.
425 Tiara controlling fully pumped system using room
stat and two (2 port) spring return zone valve with
auxiliary switches
425 Diadem/Tiara controlling gravity hot water with
pumped heating via room stat and cylinder stat.
425 Coronet controlling fully pumped system via room
stat,cylinder stat and using a 2 port spring return valve
with auxiliary switch on heating circuit.
425 Tiara controlling fully pumped system using a mid
position valve via room stat and cylinder stat.
425 Diadem/Tiara controlling gravity hot water with
pumped heating using a 2 port spring return valve with
changeover auxiliary switch on the hot water circuit.
E
N
L
MAINS
SUPPLY
N
L
1
2
3
4
5
6
N
C
CALL
SAT
CALL
SAT
C
FROST
STAT
IF
FITTED
C
CALL
ROOM
STAT
CYL
STAT
N
L
PUMP &
BOILER
ZONE
VALVE
ZONE
VALVE
