9 Repair
NGW 300 / LGW 300 / GBW 300
908
9.2.6 Replacing the flame monitor electrode
9.2.6.1 Disassembly
1. Dismantle the burner head (see 8.5.1.1).
ATTENTION
During the following procedure, please ensure that the
ignition electrodes and the flame monitor electrode
are not twisted.
2. Remove the cylinder screws (6, fig.. 907) and
dismount the heat shield (5).
3. Disconnect the flame monitor electrode’s plug
connection at the control unit and pull back the nozzle
(14) approx. 8 cm.
4. Remove the screws (8) and detach the flame monitor
electrode with the connecting line (7) approx. 7 cm.
5. Remove the shrinking hose and disconnect the
connecting line / flame monitor electrode plug.
6. Implement the measures for components when the
system is disassembled (see 9.1.1).
9.2.6.2 Installation
1. Attach a new gasket (9, fig. 907) to the flame monitor
electrode¬ (7).
2. Slide the shrinkable hose (from the replacement part
bag) onto the flame monitor connection line and
create a connection.
3. Slide the shrinkable hose over the flame monitor
electrode’s insulator (7) as far as it will go and shrink
it so that it fits well all around and creates a seal.
4. Attach the flame monitor electrode (7) with cylinder
screws (8). Tighten the screws with 5,5 Nm.
5. Attach the heat shield (5) with screws (6).
Tighten the screws with 5,5 Nm.
ATTENTION
Make sure that the ignition electrodes and the flame
monitor electrode are not twisted.
6. Check the spacing of the ignition electrodes
(see 6.3.3).
7. Check the spacing of the flame monitor electrode
(see 6.3.4).
8. Lock the sleeve (14) in place in the fan casing.
9. Mount the burner head (see 8.5.1.2).
9.2.7 Replacing the burner
9.2.7.1 Disassembly
1. Dismantle the burner head (see 8.5.1.1).
ATTENTION
During the following procedure, please ensure that the
ignition electrodes and the flame monitor electrode
are not twisted.
2. Remove the cylinder screws (6, fig.. 907) and
dismount the heat shield (5).
3. Unscrew and remove spacers (11) and safety
washers.
4. Remove the burner(10) with the gasket (12).
5. Implement the measures for components when the
system is disassembled (see 9.1.1).
9.2.7.2 Installation
1. Bring the burner (10, fig. 907) and a new gasket (12) into
the installation position and attach with spacers (11) and
safety washers. Tighten the spacers with 5.5 Nm.
ATTENTION
During the following procedure, please ensure that the
ignition electrodes and the flame monitor electrode
are not twisted.
2. Attach the heat shield (5) with cylinder screws (6).
Tighten the screws with 5.5 Nm anziehen.
3. Mount the burner head (see 8.5.1.2).
9.2.8 Disassembly and reassembly of the
burner head
9.2.8.1 Disassembly
1. Dismantle the burner head (see 8.5.1.1).
2. Dismantle the conrol unit (see 9.2.3.1).
3. Dismantle the ignition spark generator (see 9.2.4.1).
4. Disassemble the igntion electrodes (see 9.2.5.1).
5. Dismount the flame monitor electrode (see 9.2.6.1).
6. Dismount the burner (see 9.2.7.1) and remove the
back wall (23, fig. 908) with the gasket (24).
7. Screw off the gas nozzle.
8. 4Remove 4 fillister screws and serrated washers and
dismantle the hood.
9. Remove 2 fillister screws and serrated washers and
loosen the bracket (2) for the wiring harness
connector.
10. Remove the hose line to the vacuum pump (3) at the
gas mixer.
11. Disconnect the vacuum switch (3) from the electricity
supply.
12. Remove 2 screws, nuts and the vacuum switch (3).
13. Remove the cylinder screws (5) and dismount the
motor (4) with the flange (6) and the gas mixer (1).
