42
Alpha Evoke 28 and 33 - Component Replacement
8.6 FLUE TEMPERATURE SENSOR - Fig. 8.6
Gain access as described in Section 9.1.
1. Unplug the wire from the flue sensor.
2. Using a 13 mm spanner, turn the sensor 90° anti-clockwise and
withdraw it from the heat exchanger.
3. Fit the new sensor and re-assemble in reverse order.
8.7 FUSE - Fig. 8.1
The fuse is located on the PCB.
1. Gain access to the rear of the control box as described in Section 8.8.
2.
Remove the three screws securing the PCB cover and remove cover.
2. Lift out and remove the fuse. Fit a 3.15 AF fuse as a replacement.
3. Re-assemble in reverse order.
8.8 PCB - Fig. 8.1
Note:
The replacement of the gas valve or PCB must be carried out by a Gas Safe registered engineer with the use of a flue
analyser.
Gain access as described in Section 8.1.
1. Release the grommet and unplug the lead from the PCB.
2. Remove the three screws securing the PCB cover and remove cover.
3. Remove the PCB retaining screws.
4. Lift the PCB from the control panel and note the connections before unplugging the wire connections.
5. Re-assemble in reverse order. Refer to the wiring diagram in Section 9.1 for connections. When replacing the PCB
cover, ensure no wires are trapped and all wiring is secured. Secure cover with three screws - do not over tighten
6. Set the correct parameters for the correct boiler model as described in Section 6.13.
7. Test the boiler.
8.9
GAS VALVE
Note:
The replacement of the gas valve or PCB must be carried out by a Gas Safe registered engineer with the use of a flue
analyser.
Isolate the boiler gas supply and gain access as described in Section 8.1.
1. Disconnect the electrical plug from the gas valve.
2. Remove the gas pipe retaining clip and remove the pipe.
3. Disconnect the gas valve union beneath the boiler.
4. Remove the two screws from beneath the boiler, disconnect the gas valve pressure tube and lift out the valve assembly.
5. Unscrew the brass union from the top of the gas valve and transfer it to the new gas valve using a new washer.
6. Fit the new assembly and re-assemble in reverse order and test for gas tightness.
7. Light the boiler. (Refer to Commissioning, Section 6.4).
8. Test the boiler, check the ignition and test the combustion as described in Section 6.
8.10 DHW TEMPERATURE SENSOR - Fig. 8.2
Gain access as described in Section 8.1.
1. Unplug the wiring and unclip the sensor from the DHW outlet pipe as required.
2. Re-assemble in reverse order with a new sensor ensuring a good contact between the pipe and sensor.
Fig. 8.1
PCB fuse
PCB
Pressure gauge
