25
British Gas 4100 & 4125 RD2 -
Installation & Servicing
INSTALLATION
37 MID POSITION VALVE
Pumped only
Notes.
1.
Some earth wires are omitted for clarity. Ensure proper
earth continuity when wiring.
2.
For numbering of terminals on thermostats see the
manufacturer's literature.
3.
This is a fully controlled system - set the boiler
thermostat to maximum.
4.
'Switchmaster ' (Smiths) valves are similar but the wiring
is different. Consult the diagram supplied with the valve.
38 TWO SPRING CLOSED VALVES
Pumped only
Notes.
1.
Some earth wires are omitted for clarity. Ensure proper
earth continuity when wiring.
2.
For numbering of terminals on thermostats see the
manufacturer's literature.
3.
This is a fully controlled system - set the boiler
thermostat to maximum.
4.
'Switchmaster' (Smiths) valves are similar but note that
the GREY (NOT the orange) wire MUST be the one
connected to permanent L.
39 HONEYWELL 'C' PLAN
IMPORTANT
The pump must not be wired directly to the boiler.
Notes.
1.
Some earth wires are omitted for clarity. Ensure proper
earth continuity when wiring
2.
For numbering of terminals on thermostats see the
manufacturer's literature.
LEGEND
b
blue
bk
black
w
white
gy
grey
y/g
yellow/green
br
brown
r
red
or
orange
or
orange
y/g
yellow/green
gy
grey
br
brown
r
red
w
white
LEGEND
b
blue
bk
black
bk
black
br
brown
or
orange
LEGEND
w
white
r
red
b
blue
gy
grey
y/g
yellow/green
Gravity HW & Pumped CH
INST
ALLA
TION