Ideal Boilers LOGIC MAX HEAT H 18, Installation & Servicing

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Installation and Servicing
SECTION 3 - SERVICING
3.20 HEAT ENGINE REPLACEMENT
Note. To remove the flow and return pipe connections from the heat exchanger, it may be necessary to cut the pipes above the boiler.
IMPORTANT
Before starting the removal procedure, protect the gas and
electrical controls with a waterproof sheet or plastic bag.
1. Refer to Section 3.8.
2.
Remove rubber plug from base to drain the boiler using the
drain point.
3. Remove the fan / venturi assembly and place on one side.
Refer to Section 3.9.
4. Remove the burner and place on one side. Refer to Section
3.11.
5.
Remove the ignition and detection electrodes. Refer to
Sections 3.13 & 3.14.
6. Remove flow and return thermistors from locations.
7. Remove the spark generator. Refer to Section 3.15.
8. Remove the gas valve. Refer to Section 3.16.
9. Remove the 2 M5 screws retaining the gas valve mounting
bracket and transfer bracket to the new heat exchanger.
10. Pull the clips, retaining the water flow switch housing,
forward and remove the water flow switch.
11. Remove the screw securing the pipe to the heat exchanger
and remove the “c” clip. Lift the housing/return pipe
assembly upwards to disengage from the heat exchanger
return pipe elbow.
12. Remove the screw retaining the flow pipe bracket and
remove the bracket from its rear retention slot.
13. Pull the flow pipe to the right to disengage from the heat
exchanger.
14. Remove the condensate rubber pipe. Refer to Section
3.17.
15. Remove the LH heat exchanger fixing screw.
16. Pull the heat exchanger to the left to disengage the rear
retention pegs and remove the heat exchanger.
17.
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.
18. Reassemble in reverse order, ensuring the heat exchanger
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. Note. Ensure that the flow
pipe is fitted through the “V” bracket when refitting.
19. Ensure the trap/siphon is filled with water. Refer to Section
3.17.
20. Refill the boiler, ensuring rubber plug from base is re-fitted,
and drain point is fully closed.
21.
Ensure all gas valve connections are gas tight with a gas
soundness check up to the gas control valve.
22. Check operation of the boiler. Refer to Sections 2.26 & 2.27.
9
15
14
12
13
6
11
6
2
11
18
17
Shown as 180º position
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Refer also to Section 2.1 - ‘Boiler Exploded View’
10
SER
VICING