Webasto Air Top Evo 3900 Workshop Manual page 48

9 Repair
9.2.6 Change the burner and the glow plug/
flame sensor
9.2.6.1 Removal
1. Remove the heater (see 8.7.1.1).
2. Remove the casing parts (see 9.2.1).
3. Remove the control unit (see 9.2.3.1).
4. Remove the combustion and hot air blower (see
9.2.5.1).
5. Remove 2 screws (1, fig. 903) and take off the
retaining bar (2).
6. Press the grommet on the glow plug/flame sensor (8)
inwards out of the heat exchanger casing (6).
7. Press the grommet on the burner's fuel line (3 or 7)
inwards out of the heat exchanger casing (6).
8. Carefully pull the burner (3 or 7) out of the combustion
pipe (4) and take the fuel supply out of the heat
exchanger casing (6) by turning the burner.
9. Remove the retaining clip (9) and pull the glow plug/
flame sensor (8) out of the burner (3 or 7).
10. Complete the work on stripped down components
(see 9.1.1).
9.2.6.2 Installation
1. Insert the glow plug/flame sensor (8, fig. 903) into the
burner (3 or 7) (cable towards the opening for the
cable grommet) and secure it with the retaining
clip (9).
2. Insert the burner (3 or 7) into the heat exchanger (6)
in the opposite direction and insert it into the
combustion pipe (4).
3. Place the retaining bar (2) in its assembly position and
secure it with 2 screws (1).
4. Tighten the screws to 4 ± 0.4 Nm.
5. Press the grommet on the fuel line into the heat
exchanger (6).
6. Thread the cable for the glow plug/flame sensor (9)
through the opening in the heat exchanger casing (6).
7. Press the grommet into the heat exchanger.
Ensure that the glow plug cables do not form a loop in
the heat exchanger.
8. Fit the combustion and hot air blower (see 9.2.5.2).
9. Fit the control unit (see 9.2.3.2).
10. Fit the casing parts (see 9.2.2).
11. Install the heater (see 8.7.1.2).
906
Air Top Evo 3900/5500
9.2.7 Change the combustion pipe and the heat
exchanger
9.2.7.1 Removal
1. Remove the heater (see 8.7.1.1).
2. Remove the casing parts (see 9.2.1).
3. Remove the control unit (see 9.2.3.1).
4. Remove the overheating sensor (see 9.2.4.1).
5. Remove the combustion and hot air blower (see
9.2.5.1).
6. Remove the burner (see 9.2.6.1).
7. Remove 2 screws (1, Fig. 903) and pull the
combustion pipe (4) out of the heat exchanger (6).
8. Remove and discard the round sealing ring (5) from
the heat exchanger (6).
9. Complete the work on stripped down components
(see 9.1.1).
9.2.7.2 Installation
1. Fit a new round sealing ring (5, fig. 903) into the heat
exchanger (6).
2. Secure the combustion pipe (4) with 2 screws on
opposite sides (1).
3. Tighten the screws to 4 ± 0.4 Nm.
4. Fit the burner (see 9.2.6.2) .
5. Fit the combustion and hot air blower (see 9.2.5.2).
6. Fit the control unit (see 9.2.3.2).
7. Fit the overheating sensor (see 9.2.4.2).
8. Fit the casing parts (see 9.2.2).
9. Install the heater (see 8.7.1.2).