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27
221473B
2 Servicing
2.1 Isolation and Access
Before commencing, refer to Section 1.1.
Isolate the boiler from the electrical supply and close the gas
service cock, refer to Section 1.3.
Remove the outer case and the cover of the inner case, refer to
Sections 1.4 and 1.5.
Remove the fan from the flue collector, refer to Section 4.1.
Remove the flue collector secured by two screws, see diagram
4.1.
Remove the main burner, refer to Section 4.2.
2.2 Cleaning Heat Exchanger
Place a sheet of paper or similar in the combustion chamber, to
act as a collector for deposits removed.
Brush the heat exchanger with a suitable brush, remove paper
together with any debris
2.3 Cleaning Main Burner
Use a vacuum cleaner or suitable brush to clean the burner
thoroughly, making sure that all burner ports are clear and
unobstructed.
Do not use a brush with metallic bristles.
2.4 Service Checks
Inspect the spark and sensing electrodes, Clean or renew if
necessary, refer to Sections 4.4, 4.5, 4.6 and 4.7.
Check the main injector, cleaning or renewing as necessary,
refer to Section 4.3.
Before replacing any of the parts removed during servicing,
inspect the condition of all seals and joints, renewing them as
necessary.
Check the condition of the combustion chamber insulation. If
renewing, refer to Section 4.30.
Check that the spark and sensing gaps are as shown in diagram
2.1.
2.5 Initial Assembly
Make sure that the main burner is located on the main injector
and is horizontal, the tips of the rearmost blade under the two
burner guides.
The combustion chamber front panel should be fitted loosely,
then the flue collector also fitted loosely, making sure that it is
seated correctly on the heat exchanger and over the top edge
of the front panel.
To fit the fan, locate it into the rear bracket and ease the flue
elbow onto the fan outlet and secure with the two screws, see
diagram 4.1.
When fitting the flexible tubes to the air pressure switch make
sure the lower (red) tube from the fan connects to the lower
connection of the switch.
Connect the electrical cables to the fan, the polarity of the two
connectors is not important, see diagram 4.1.
Secure the flue collector and combustion chamber front panel
by tightening the wing nut and screws, evenly, see diagrams 4.1
and 4.2.
2.6 Operational Checks
Light the boiler, carry out operational checks and any necessary
adjustments as described in “Commissioning” in the Installation
Instructions.
2.7 Completion
Hook the outer case on at the top and secure with the screws
previously removed, see diagram 1.2.
Close the door.
1 General Data
1.6 System Pressures and Draining
All parts containing water of the central heating circuit within the
boiler, are under the system pressure. Before any parts of this
circuit are disconnected, reduce the system pressure at the
external draining tap, turn the central heating isolating valves
off, and drain at the drain points on the appropriate valves, see
diagram 1.1.
All water containing parts of the domestic hot water circuit of the
boiler will be under the supply water pressure. Before any parts
of this circuit are disconnected, turn the domestic cold water
isolating valve off, open the hot water taps to reduce the water
pressure in the boiler, and drain the boiler at the valves, see
diagram 1.1.
After replacing any water containing part of the central heating
circuit, make up the water loss, vent all air and pressurise the
system. Refer to “Commissioning” in the Installation Instructions.
Check for water soundness and that the safety valve seats
without leaking.
5017
5059
Diagram 2.1
SPARK AND SENSING GAP
3
+0.5
-0.5
-0.5
5
+0.5
-0.5
5
+0.5
SENSING
ELECTRODE
SPARK
ELECTRODE
EARTH
ELECTRODE