Jet 120i Installation & Servicing Instructions Manual page 13

NOTES: Control terminal numbering may differ from those shown.
Refer to instructions with controls selected.
A double pole isolating switch must be installed in the mains supply.
All earth connections must be connected back to the mains earth supply.
Fig. 08: Schematic Wiring Diagram - Basic 2 x 2 port valve system ( 'S' plan )
NOTES: Control terminal numbering may differ from those shown.
Refer to instructions with controls selected.
A double pole isolating switch must be installed in the mains supply.
All earth connections must be connected back to the mains earth supply.
Fig. 09: Schematic Wiring Diagram - 3 port mid position valve system. ( 'Y' plan ) N.B. Must be used in con-
junction with 2 port zone valve supplied
Zone valve (HTG)
G Br Bl 0
GY
1 2 3
(Supply)
L N
1 2
1 2 3 4 5 6 7 8 9 10
1 2 3
L N
HTG DHW
ON ON
Programmer
3 Port Zone valve
G W Bl 0
GY
2 3
(Supply)
L N
1 2
1 2 3 4 5 6 7 8 9 10
1 2 3
L N
HTG DHW DHW
ON ON OFF
Programmer
Cylinder terminal block
1 2 3
3
Room stat
1 3 2
2
3 4 5 6 7 8 9 10
2 3
L N
Boiler
Cylinder terminal block
1 2 3
3
3 4 5 6 7 8 9 10
2 3
2
1 3 2 L N
Room stat Boiler
Zone valve (DHW)
(supplied)
G Br Bl 0
1 2
Junction box
L
3
N
Pump
Zone valve (DHW)
(supplied)
G Br Bl 0
1 2
Junction box
L
3
N
Pump
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