Alpha InTec2 25XE Installation And Servicing Instruction page 43

12. Lift the heat exchanger up and forwards to release it from its fixing bracket and withdraw it from the boiler.
13. Transfer the condensate tray, the electrode previously removed, sensors, retaining latches ('A' in Fig. 6.5) to the new
heat exchanger using new seals
14. 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
Check the condition of all other seals before reassembling.
15. 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,
7.14 PRESSURE GAUGE - Fig. 7.1
Gain access to the boiler as described in Sections 7.1 and 7.2.
1. Withdraw the retaining clip securing the pressure gauge sensor (just to the left of the automatic air vent) and withdraw
the sensor.
2. Remove the main cable grommet in the bottom panel and remove the sensor tube.
5. Depress the two lugs on the pressure gauge and pull it out of the control panel.
4. Fit the new gauge using a new 'O' ring on the connection if necessary.
5. Refill and pressurise the system. (Refer to Commissioning, Section 5.1).
7.15 PRIMARY TEMPERATURE SENSOR and OVERHEAT THERMOSTAT - Fig. 6.7
Gain access and drain the boiler heating circuit as described in Sections 7.1.
1. Unplug the wiring and unscrew the sensor. Re-assemble in reverse order with a new sensor. Do not overtighten.
2. Refill and pressurise the system. (Refer to Commissioning, Section 5.1).
7.16 AUTOMATIC AIR VENT - Fig. 6.7
Gain access and drain the boiler heating circuit as described in Sections 7.1 and 7.2.
1. Turn the automatic air vent anticlockwise and lift it out.
2. Insert the new air vent using a new washer and turn it clockwise to lock it in position.
3. Refill and pressurise the system. (Refer to Commissioning, Section 5.1).
7.17 PUMP HEAD - Fig. 6.7
Gain access and drain the boiler heating circuit as described in Sections 7.1 and 7.2.
1. Disconnect the two plugs from the pump.
2. Using a 4 mm Allen key remove the four socket head screws suring the pump head to the body.
3. Reassemble the new pump head in reverse order ensuring, re-connecting the two plugs.
4. Refill and pressurise the system. (Refer to Commissioning, Section 5.1).
7.18 PRIMARY PRESSURE SWITCH - Fig. 6.7
Gain access and drain the boiler heating circuit as described in Sections 7.1 and 7.2.
1. Disconnect the wiring from the pressure switch.
2. Withdraw the retaining clip on the left side of the switch and lift the switch upwards to remove.
3. Insert a new switch and re-assemble in reverse order.
When connecting the wiring to the new switch the polarity of the wires is not important.
7.19 SAFETY VALVE - Fig. 6.7
Gain access and drain the boiler heating circuit as described in Sections 7.1 and 7.2.
1. Disconnect the clear plastic tube from the pressure relief valve.
2. Remove the retaining clip securing the expansion relief valve and pull the valve forwards to remove.
3. Re-assemble in reverse order.
4. Refill and pressurise the system. (Refer to Commissioning, Section 5.1).
Alpha InTec² 25XE and 28XE - Component Replacement
43