Bosch Worcester 15SBi Installation And Servicing Instructions page 26

Fig.48. Rear Control Board Cover.
1
1. Control Board Cover Fixing Screws (4)
2. Rear Connections Cover Fixing Screws (2)
3. Rear Connections Cover
4. Control Board Cover
5. Facia
6. Pressure gauge
7. clock clips
15.4.9 Control Board
Remove the facia bottom panel and carefully disconnect all the
electrical connections. Refer to Fig. 11 and 12.
Lower the facia panel and remove the splash cover. Refer to
Section 14.3.
Disconnect the earth connection at the appliance. Refer to Fig. 33.
Remove the rear connection cover, unplug the connections and
release the cable clamps.
Unscrew the four screws to remove the metal cover. Refer to Fig. 48.
Lift out the control board.
15.4.10 Clock
Remove the cabinet front panel and lower the facia panel.
Remove the splash cover and the rear connection cover.
Disconnect the clock/programmer. Refer to Fig. 34
Fig.49 . Heat exchanger (24SBi)
3
4
5
6
7
1. Auto Air Vent
2. Inner Casing Seal
3. Auto Air Vent Assembly Clip
4. Gas to Water Heat Exchanger
5. Flow Sensor Clip
6. Primary flow Sensor
2
5
1
2
9
8
7. Heat Exchanger Support
Bracket
8. Overheat Thermostat
9. Overheat Thermostat
Fixing Screws
3
7
6
15.4.11 Heat Exchanger
Drain the appliance as described in Section 15.3 preceding.
Remove the combustion chamber, fan and flue hood as
described in Section 14.3, Inspection and Servicing.
Remove the temperature sensors as described in 15.4.15, 16, 17.
Refer to Fig.49.
Remove the auto-air vent and connecting pipe.
Release the connections and remove the heat exchanger
15.4.12 Pump
Remove the cabinet front panel and lower the facia panel.
Drain the appliance as described in Section 15.3 preceding.
Release the water connections and remove the pump. Refer to
Fig.50.
Disconnect and transfer the electrical connections to the new
pump. Set the pump speed to that of the replaced pump. Do not
forget to fit the gaskets at the connections.
Alternatively replace the pump head only by unscrewing the
four Allen screws.
Fig.50 . Circulating pump
Unscrew union fittings
Allen screws (4)
remove if changing
pump head only
Pump
Electrical
connection
cover
26
4
Expansion vessel
Unscrew union
fitting