Vaillant ecoTEC plus Installation And Maintenance Instructions Manual page 20

11 Troubleshooting
11.5.2 Replacing the gas-air mixture unit
1. Remove the gas-air mixture unit. (→ Page 17)
2. Install the new gas-air mixture (→ Page 19).
11.5.3 Replacing the heat exchanger
1. Remove the side section. (→ Page 9)
2. Remove the gas-air mixture unit. (→ Page 17)
C
B
1
2
D
3. Remove the flow pipe (1).
4. Remove the return pipe (2).
B
5. Remove the gas pipe.
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A
E
A
B
3
6. Undo the clip underneath the condensate tray (4).
7. Undo the two screws (3).
5
C
B
8. Lift the heat exchanger up slightly and remove it to-
gether with the condensate tray.
9. Remove the ignition transformer (5).
10. Replace all the seals.
11. Install the new heat exchanger in reverse order.
11.5.4 Replacing the main PCB
A
1. Open the electronics box. (→ Page 11)
2. Pull all of the plugs out from the PCB.
3. Undo the clips on the PCB.
4. Remove the PCB.
Installation and maintenance instructions ecoTEC plus 0020200871_00
A
4
A
C
C
D
B
A