24
2.5 Connect the Water System
Read and observe recommendations in Section
1
.6 and see Fig.
11
.
Secure the combination reducing valve - a wall
brac
k
et is provided in the accessory pac
k
. 22mm
copper tube is recommended for both the inlet
and outlet connections. A 22mm balanced
pressure outlet is built-in to this valve for
supplying showers etc. It can be sited away from
the boiler e.g. where the water mains enters the
dwelling, to assist with providing reduced
pressure to all the system.
P
osition the cross fitting c/w with expansion relief
valve downstream of the reducing valve-see Fig.
11
. Ensure the flow direction is correct - arrows
indicate the direction of flow.
C
onnect the tundish
within
5
0cm of the relief valve. NB The valve can
be rotated to give the best pipe run to the tundish.
Select a location for the expansion vessel within
reach of the
1
m flexible connector and fix the
expansion vessel using the brac
k
et provided.
Avoid sharp bends or “
k
in
k
s” in the flexible
connector and ensure there is service access to
the chec
k
ing/charging point.
Future servicing operations will be simplified if the
cross fitting/relief valve and the expansion vessel
can be sited above the DHW store as indicated in
Fig.
11
.
CH System Connections
The flow connection is on the
L
H side of the unit.
The 22mm flow pipe supplied with the cylinder
provides clearance for future maintenance of the
immersion heater. Ensure this pipe is pushed fully
home into the “Techtite” joint. The return
connection is low down at the front centre.
Pressure Relief Valve (Primary)
A pressure relief valve set at 3.0 bar is fitted to the
Heat Engines primary circuit. Trim the supplied
15
mm branch pipe to length before fitting - See
Fig.
1
0.
2.6 Connect the Power Supply
WARNING – THIS BOI
L
ER MUST BE EARTHED
Wiring must comply with the current IEE Wiring
Regulations. The supply cable must be 3-core
0.
75
sq. mm (24/0.2 mm) to BS6
5
00 Table
1
6.
The supply must be of 230V –
5
0Hz. A 3A-fused
double pole-isolating switch may be used, having
a minimum contact separation of 3 mm in both
poles, providing it serves only the boiler and its
system controls. Alternatively a 3A 3 pin fused
plug may be used.
Secondary Circulation
A pumped secondary circuit, if required, can be
connected by teeing into the 22 mm DHW Outlet pipe
and the 22 mm
C
old Inlet pipe.
Note:
This is not
recommended for models having a secondary store of
less than
15
0 litres.
A single chec
k
valve (spring loaded type) should be
fitted in the return from the secondary circuit. All
component parts of a secondary circuit must be suitable
for operation at temperatures up to 6
5
°
C
and pressures
up to
8
bar.
0
0
2
4
6
8
10 12 14 16 1
8
20 22 24 26 2
8
30 32 34 36 3
8
40
1
2
Pump Head
Flow litres/min.
Graph of Central Heating Head vs. Flow
3
4
m
MAX0063A
3
RWC
From
secondar
y
circuit
To
secondar
y
circuit
Chec
k
Valve
Fig.
1
2
© Baxi Heating UK Ltd 2015