27
Grant Euroflame Condensing External Modules
Connect the power supply
6.7
Connect the fuel supply
6.8
6 - BOILER INSTALLATION
The expansion vessel fitted is supplied with a charge
pressure of 1.0 bar (equivalent to a max. static head of
10.2 metres). The charge pressure must not be less
than the actual static head at the point of connection.
Do not pressurise the vessel above 1.5 bar.
The air pressure in the vessel must be checked annually.
The central heating system volume, using the expansion
vessel as supplied, must not exceed the recommended
volumes. If the system volume is greater, an extra
expansion vessel (complying with BS 4841) must be
fitted as close as possible to the central heating return
connection on the boiler. The charge pressure of the extra
vessel must be the same as the vessel fitted in the boiler.
Refer to BS 7074:1 for further guidance.
The air charge pressure may be checked using a tyre
pressure gauge on the expansion vessel Schraeder
valve. The vessel may be re-pressurised using a
suitable pump. When checking the air pressure the
water in the heating system must be cold and the
system pressure reduced to zero.
It is recommended that the boiler should be connected
to a switched mains power supply from an external
timer or control system.
1 Check the thermostat phials are pushed fully into
the thermostat pocket on the side of the boiler.
2 Remove the overheat thermostat reset cap and undo
the three screws securing the combined boiler/overheat
thermostat cover and lift off the cover.
3 Withdraw the cable support bushes from the cover.
Pass the burner supply cable through one of the
bushes and connect it to the boiler (control)
thermostat (refer to Fig. 23) as follows:-
Brown to terminal 1 of the control thermostat.
Green/yellow and earth fly lead from the boiler
casing to the earth terminal, marked on the
control thermostat.
4 Pass a switched mains power supply through the other
cable support bush and connect it to the overheat
thermostat as follows:-
Switched live (brown) to terminal C on the
overheat thermostat.
Earth (green/yellow) and remaining earth fly lead
from casing to the earth terminal, marked on
the overheat thermostat.
Sealed system expansion vessel pressure
6.6
The neutral (blue) wire from the burner supply
must be linked to the incoming neutral of the
switched mains supply using a single connector
(not supplied).
Do not connect the neutral wires to either of the
two thermostats.
5 Connect a link between terminal 2 on the overheat
thermostat and terminal C on the control thermostat.
6 There is no connection to terminal 1 on the
overheat thermostat or terminal 2 on the
control thermostat.
7 Position the support bushes so as not to strain the
connections when the cover is replaced.
Place the cover in position locating the bushes at
the same time.
Note: It may be necessary to rotate the thermostat
knob to engage it on the operating spindle as the
cover is replaced.
8 Secure the cover in position by tightening the three
screws. Refit the overheat thermostat reset cap.
Tighten the cable support bush nuts to secure the
cables.
9 Ensure all external wiring is adequately supported.
Do not switch on the electricity supply at this
stage.
See Fig. 6
If a two pipe system is to be used refer to Section 4.4.6.
1 Remove the oil inlet plug from the fuel pump and
connect the elbow of the flexible fuel hose supplied
with the boiler.
2 Connect the flexible fuel hose to the rigid supply
using the adaptor supplied. The supply enters the
enclosure through one of the holes in the bottom of
the side panels.
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