Alpha InTec2 26CE Installation And Servicing Instructions page 38

6.5 CLEANING THE HEAT EXCHANGER
Cleaning the heat exchanger is only necessay if the air flow test pressure has reduced by more than 40% as
described in Section 5.4.
Gain access and drain the boiler heating circuit as described in Sections 7.1 and 7.2.
1. Remove the condensate trap assembly as described in Section 7.11.
2. Remove the electrode as described in Section 7.3 and check its condition.
3. Remove the three screws securing the fan air/gas manifold and remove the two spring clips at either end of the gas
pipe, removing the pipe and manifold together.
4. Unscrew the flue sampling point cap and remove the complete fitting from the top of the case.
5. Disconnect the flue sensor wires and remove the lower retaining screw on the flue manifold assembly.
6. Pull down the flue manifold assembly and withdraw the complete assembly.
7. Unplug the primary sensor and fan wires.
8. Unlatch the two clips 'A' in Fig. 6.5 securing the fan and burner cover and remove the complete assembly.
9. Disconnect the earth wire from the burner and lift the burner out of the heat exchanger.
10. Remove the retaining clips from the flow and return pipes at the heat eaxchanger and hydro block housing and remove
the pipes.
11. Remove the two screws securing the bottom rear of the heat eaxchanger to the condensate sump.
12. Lift the heat exchanger up and forwards to release it from its fixing bracket and withdraw it from the boiler.
13. Remove the four screws securing the condensate sump to the heat exchanger and remove it.
14. With the correct cleaning tool, clean the heat exchanger, inserting the tool in the bottom of the heat exchanger between
the pins in both directions to remove any deposits.
15. After cleaning, flush the heat exchanger from both sides with running water in order to remove any residue,
16. Reassemble in reverse order.
Note: The following items must be replaced with new ones:
• Burner seal
• Condensate tray seal
• Heating flow and return pipes 'O' rings
• Electrode gasket if removed
17. Check again the air flow through the heat exchanger as described in Section 5.4, recording the new pressure value and
complete the service record at the back of these instructions,
6.6 RE-ASSEMBLE THE BOILER
1. Replace the burner seal ensuring it is located correctly around the burner edge.
2. Replace the burner ensuring it is located correctly in the heat exchanger and re-connect the earth wire.
3. Replace the burner cover and fan assembly securing with the two latches then re-connect the fan wire.
4. Replace the flue manifold assembly and secure to the condensate tray with the fixing screw. Re-connect the flue sensor
wire.
5. Replace the flue sampling point connection to the boiler casing and flue manifold assembly using the foam seal
previously removed. Replace the flue sampling point cap and secure it with the screw previously removed.
6. Replace the air/gas manifold to the fan (using the 'O' ring previously removed).
7. Replace the condensate trap and connection hoses. Partially fill the trap before replacing.
8. Check all the connections are sound and re-commission, Sections 5.3 and 5.8.
9. Raise the control panel and clip into place.
10. Place the front case panel in position and secure with the two screws previously removed.
11. Refit the control panel cover and secure in position with the two screws and cover plugs.
12. Carry out a full calibration procedure (refer to Section 5.13) if the burner and electrode have been cleaned or replaced.
13. Check the operation of the boiler. (Refer to Sections 5.5 and 5.6).
14. Return all controls to their original settings.
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Alpha InTec² 26E, 30CE and 35CE - Routine Servicing