Keston Combi 30 - Heat Engine Renewal

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SERVICING
Keston Combi - Installation and Servicing
72 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.
12. Undo the inlet pipe union nut and remove the retaining spring
clip and remove pipe.
13. Undo the ow pipe union nut and remove pipe.
14. Remove the condensate rubber pipe. Refer to Frame 56, no. 2.
15. Remove the two heat exchanger xing screws.
16. Remove 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 both the ow and return
pipe connections, ensure clip is oriented to correctly match
connecting pipe diameters.
18. Ensure the trap/siphon is lled with water. Refer to Frame 56.
19. Rell the boiler. Refer to Frame 22.
20. Check operation of the boiler. Refer to Frame 36.
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove the fan / venturi assembly and place on one side.
Refer to frame 46.
4. Remove the burner and place on one side. Refer to Frame
48.
5. Remove the ignition and detection electrodes and diverter
actuator head. Refer to Frames 51, 52 and 55.
6. Remove the spark generator. Refer to Frame 53.
7. Disconnect ue thermostat.
8. Remove the gas valve. Refer to Frame 54.
9. Remove the expansion vessel. Refer to Frame 73.
10. Remove the no ow thermistor. Refer to Frame 71.
11. Remove the 2 M5 screws retaining the gas valve mounting
bracket and transfer bracket to the new heat exchanger.
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SERVICING
207895-2.indd 55 02/01/2013 09:38:48