Zanussi ULTRA COMBI 35 Installation And Servicing page 52

68 HEAT ENGINE RENEWAL
Refer also to Frame 6 - 'Boiler Exploded View'
IMPORTANT
Before starting the removal procedure, protect the gas and electrical controls with a waterproof sheet or plastic bag.
1. Refer to Frame 43.
2. Drain the boiler. Refer to Frame 57.
3. Remove the fan / venturi assembly and place on one side.
Refer to Frame 44.
4. Remove the burner and place on one side. Refer to Frame 46.
5. Remove the ignition and detection electrodes. Refer to
Frames 48 and 49.
6. Remove the spark generator. Refer to Frame 50.
7. Remove the gas valve. Refer to Frame 51.
8. Remove the expansion vessel. Refer to Frame 69.
9. Remove the flow and return thermistor. Refer to Frame 47
and 67.
10. Remove the 2 M5 screws retaining the gas valve mounting
bracket and transfer bracket to the new heat exchanger.
11. Undo the pump union nut and remove pipe.
12. Remove the two retaining spring clips and remove pipes.
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SERVICING
13. Remove the condensate rubber pipe. Refer to Frame 53, no. 2.
14. Remove the two heat exchanger fixing screws.
15. Remove the Heat exchanger, slide out of location bracket.
16. If replacement sump required: Rotate heat exchanger assembly
180º. Place new sump onto heat exchanger, ensuring correct
orientation and seal is in place. Then gently apply pressure to
the base of the sump at each tab fixing point and engage tabs
onto the heat exchanger.
17. Reassemble in reverse order, ensuring the heat exchanger LH
retaining bracket is correctly positioned. Replace any new 'o'
rings supplied with new heat exchanger and replacing gaskets
or seals if any sign of damage is evident. When replacing the
spring clips located on the return pipe connection, ensure clip is
oriented to correctly match connecting pipe diameters.
18. Ensure the trap/siphon is filled with water. Refer to Frame 53.
19. Refill the boiler. Refer to Frame 24.
20. Check operation of the boiler. Refer to Frames 32 & 33.
Shown as 180º position
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Installation and Servicing