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Service Call 0844 736 9138, Technical Help (Chargeable) Call 0906 802 0253
19.1 General
The replacement of parts described in sections
"Combustion block" will require the removal of
the burner module assembly and the replacement
of seal and self locking nuts.
Replacement parts that have associated components that need
replacing on removal, i.e. ‘O’ ring, seals, gasket, etc., will be
supplied and should be fi tted.
• Before replacing any parts of the boiler, isolate from the
mains electric supply and turn off the gas at the gas service
isolation valve on the boiler.
Unless stated otherwise parts are replaced in the reverse order
to removal.
• After replacing any parts, always test for gas soundness and
if necessary carry out functional test of the controls.
19.2 Boiler Access
For replacement of parts, the front casing panel of the boiler will
need to be removed.
• To remove, undo the two screws on the underside of the
front casing and open the control box door. Remove the two
front panel retaining screws, which are now accessible, and
remove the front panel.
19.3 Viewing window
3
4
5
2
1
Key
1 Fibre washer
2 Steel washer
3 Glass
4 Steel washer
5 Circlip
• Remove the circlip (5).
• Remove the steel washer (4).
• Remove fi bre washer (1).
• Remove the glass (3).
19.3.1
Expansion vessel
2
C
2
5
1
B
3
4
Key
1 Connector (fl exible hose)
2 Expansion vessel
3 Upper support bracket
4 Retaining screw
5 Gasket
Drain the boiler heating circuit as described in the appropriate
chapter "Draining".
• Remove the two screws (4).
• Undo the connector (1) at the base of the vessel.
• Remove the expansion vessel (2).
• Fit a new gasket between the expansion vessel and
connector.
• Refi ll, vent and pressurise the boiler.
