Glow-worm Ultracom2 cxi - Manual (Page 53)

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MAINTENANCE
Legend
1 Igniter unit retaining bracket
2 Igniter unit
3 Igniter unit retaining screw
4 Igniter unit electrical connector
5 Electrode / igniter unit connection cable
6 Earth cable
7 Spark electrode cap 8 Spark electrode retaining screw
9 Spark electrode gasket
10 Spark electrode
11 Combustion burner door assembly
12 Combustion burner door assembly - nut
13 Combustion burner door assembly - seal
14 burner gasket
15 burner
16 burner retaining screw
17 Heat exchanger retaining screw
18 Heat exchanger retaining bracket
19 burner gate retaining screw
20 Thermal fuse connection
21 Heat exchanger
22 Heat exchanger retaining bracket
23 Heat exchanger retaining screw
24 Heating return pipe
25 Heating return pipe retaining clip
26 Return heating temperature sensor
27 Heating flow pipe
28 flow heating temperature sensor
29 Heating flow pipe retaining clip
30 Gas valve retaining screw
31 Gas valve
32 Gas valve gasket
33 fan
34 fan electrical connection
35 fan/burner gasket
36 Gas pipe
37 Gas valve electrical connection
38 fan retaining screw
19.5.1 Spark electrode
• Disconnect the electrode cap (7) and the earthing cable (6).
• Remove the 2 spark electrode retaining screws (8).
• Carefully remove the electrode (10) from the combustion
chamber.
• Remove the gasket (9).
• Check that the distance between the 2 electrodes is between
3.5 and 4.5 mm.
• Install the electrode and a new gasket.
19.5.2 Igniter unit
• Remove the ignition lead (2).
• Remove electrical connections (4).
• Loosen the screws (3) located on the igniter unit (2).
• Remove the igniter unit (2).
19.5.3 Removing the combustion/burner door
assembly
b
Warning: The burner door seal (13) must be
replaced each time the combustion/burner door
assembly is removed.
• Disconnect the spark electrode cap (7) from the igniter unit.
• Disconnect the gas supply pipe (36) at the gas valve.
• Remove the electrical connectors from the gas valve (37)
and the fan (34).
• Remove the retaining screw of the silencer.
• Loosen the 4 nuts (12).
• Remove the combustion/burner door assembly from the heat
exchanger (11).
• The studs (19) must not be damaged. If damaged you will
need to replace the heat exchanger.
• The combustion/burner door assembly insulation should be
inspected and replaced if damaged.
19.5.4 burner
• Remove the 3 burner retaining screws (16).
• Remove the burner (15) and the gasket (14).
• Fit the new burner and the new gasket.
19.5.5 Heat exchanger
b There will be water in the heat exchanger.
Carefully ease heat exchanger out.
• Drain the boiler heating and hot water circuits as described in
the appropriate chapter "Draining".
• Remove the flue connection.
• Undo the two screws located on the top of each side panel.
• Remove the thermal fuse connector (20).
• Remove the 2 heating pipe retaining clips (25) and (29).
• Release the heating pipes (24) and (27) from the heat
exchanger.
• Release the condensate trap pipe from the heat exchanger.
• Remove the combustion/burner door assembly (11)
refering to chapter "Removing the combustion/burner door
assembly".
• Unscrew the 4 retaining screws (17) and (23) and remove
the 2 retaining plates (18) and (22) from the heat exchanger.
• Pull the heat exchanger towards you to extract it from its 2
side rails.