45
8.20 DHW HEAT EXCHANGER - Fig. 7.6
Gain access and drain the boiler heating and hot water circuits as described in Sections 8.1 and 8.2.
1. Remove condensate trap as in Section 8.11.
2. Using a 4 mm Allen key remove the two bolts securing the Plate heat exchanger to the hydro block assembly.
3. Slide the heat exchanger to the left hand corner of the boiler and rotate it forwards from its right hand side through the
centre of the boiler to remove.
4. Remove and replace the seals in the back of the hydro block housing.
5. Replace in reverse order making sure that the printed writing on the heat exchanger is at the top.
6. Refill and pressurise the system. (Refer to Commissioning, Section 6.1)
8.21 DIVERTER VALVE MOTOR - Fig. 8.2
Switch the boiler to Standby ( ).
Gain access as described in Section 8.1.
1. Push the clip on the plug and pull the plug from the diverter motor.
2. Lift the motor upwards and forwards to remove from the valve body.
3. Test the boiler in heating and hot water mode to ensure the motor is correctly engaged with the diverter valve spindle.
8.22 DIVERTER VALVE CARTRIDGE - Fig. 8.2
Gain access and drain the boiler heating circuit as described in Sections 8.1 and 8.2.
1. Remove the diverter valve motor as described in Section 8.21.
2. Using the supplied tool and a suitable spanner turn the diverter valve cartridge anticlockwise until its retaining lugs hit
the stops.
3. Withdraw the cartridge taking care not to spill any water onto any electrical components.
4. Insert the new cartridge with the locating lug at the top and push firmly into place. Using the supplied tool and a suitable
spanner turn the cartridge clockwise until the retaining lugs are locked into position.
5. Pull the diverter pin fully out into the CH position and connect the diverter motor as in Section 8.21.
6. Test the boiler in heating and hot water mode to ensure the motor is correctly engaged with the diverter valve spindle.
8.23 EXPANSION VESSEL - Fig. 7.6
Note:
Check that the pressure of the new vessel is 1 bar before it is installed.
Gain access and drain the boiler heating circuit as described in Sections 8.1 and 8.2.
1. Remove the top side panel fixing screw.
2. Disconnect the copper pipe from the bottom of the vessel.
3. Remove the top fixing nut from the air valve.
4. Remove the bottom fixing screw and withdraw the vessel taking care not to spill any water into other boiler components.
5. Re-assemble in reverse order.
6. Refill and pressurise the system. (Refer to Commissioning, Section 6.1).
8.24 COMBUSTION CHAMBER INSULATION
1. Remove the complete burner/fan/air inlet assembly as described in Routine Servicing, Section 7.3.
2. Open the three spring clips (see Fig. 7.5) and carefully lift off the insulation panel. It may be necessary to remove the
electrode assembly first as described in Section 8.3.
3. To remove the rear insulation panel, open the four clips and prise out the panel.
4. Fit the new panel(s) and re-assemble in reverse order referring to Routine Servicing, Section 7.5.
5. Test the boiler, check the ignition and test the combustion as described in Section 7.
8.25 ALPHA CONTROLS (if fitted)
Refer to section 4.11 on the connection options for boiler controls.
Alpha Evoke 28 and 33 - Component Replacement
