Technical data

15
SERVICING INSTRUCTIONS
ROUTINE CLEANING ANS INSPECTION
To ensure the continued efficient and safe opera-
tion of the boiler it is recommended that it is
checked and serviced at regular intervals. The fre-
quency of servicing will depend upon the particu-
lar installation conditions and usage, but in gen-
eral once a year should be enough.
It is the law that any servicing is carried out by a
competent person.
Service Check and Preparation.
• Operate boiler and check for any faults that
need to be put right.
• Isolate boiler from the gas and electrical supplies.
• On completion check all gas carrying parts for
soundness with leak detection fluid.
• The maximum domestic hot water flow rate is 12
litres/minute.
• Remove boiler casing as follows:
Upper front panel
• Disengage the two 'quarter turn' fasteners by
turning the heads of the screws a quarter of a turn
towards the centre of the boiler.
• Carefully lower the panel down on its hinge until
it is horizontal.
• Turn both plastic catches to release upper front
panel.
• Remove upper front panel by pulling forward at
the bottom and lifting off.
Note: The upper front panel is retained by a plastic
safety strap, disengage this before removal.
Side panels
• From below boiler, unscrew and remove black
plastic screws securing side panels to the boiler.
• Prise out black plastic inserts and lift panel off
boiler.
Combustion chamber
• Loosen two wing nuts on combustion chamber
cover.
• Disengage retaining lugs from holes in either side
of combustion chamber and move rods away to
clear combustion chamber sides, see diagram 19.
• Unclip two toggle clips holding upper part of
combustion chamber in place.
• Holding both sides, pull chamber forward to re-
lease it from underside of heat exchanger and out
of boiler.
• Take care not to damage insulation material on
inside faces of combustion chamber.
Cleaning the burner
• Pull off leads to ignition electrode.
• Pull off lead to flame sense electrode.
• Unscrew and remove screw holding earth lead
to flame sense electrode.
• Undo main gas supply nut from main burner.
• Unscrew and remove locking nut from both main
gas connection and burner pressure tapping point.
• Lift front edge of burner until tapping point and
gas supply connection are free. Remove burner
from boiler taking care to retain both fibre washers
and seal on gas supply for use on reassembly.
• Unscrew and remove two injector bar retaining
screws and separate injector bar from burner.
• Examine and clean injectors as necessary.
Note: Do not use a wire or sharp instrument on the
holes.
• Replace burner in reverse order to removal.
Heat exchanger
• After removal of burner, examine heat ex-
changer for any blockages or build up of deposits.
• Clean using soft brush or vacuum cleaner.
Important: Take care not to scratch or otherwise
damage painted surface of heat exchanger.
Reassembly of parts removed for servicing
• Replace all parts in reverse order to removal.
Flue system
• Check externally to make sure flue is not blocked.
• Inspect flue system to make sure all fittings are
secure.
Operation of fan
• Switch on electrical supply and turn on gas.
• Switch boiler On/Off switch to 1 (On).
• Light burner by opening a hot tap.
• Without upper front panel in place, burner should
be prevented from lighting by air flow detection
system.
• Refit upper front panel.
• Check that fan runs when burner is lit and stops
when it goes out.
Cold water inlet filter
• Drain down hot water circuit of boiler as follows:
• Close isolating valve on cold water inlet connec-
tion, see diagram 5.
• Open one or more hot water taps to drain boiler.
• Undo connecting nut from cold water inlet con-
nection to gain access to filter.
• Remove restrictor, then filter from cold water in-
let connection.
• Clean and inspect filter, replace if necessary.
• With both flow restrictor and filter in place, re-
connect pipe to inlet connection and tighten.
• Fully open isolating cock on cold water inlet con-
nection and check for leaks.
Operation of water valve
• With the Summer/Winter control in the 'Summer'
position, slowly open a convenient tap until boiler
lights.
• Measure water flow, it should not be greater than
3,5 litres/minute.
• If necessary, replace diaphragm.
• Replace all outer panels.
Diagram 19
Des 047