Bosch Singular 4000 - Control Board; Sensor, Heating;Return; Sensor, DHW; Exhaust Temperature Sensor_T4 (Blue)

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Service Manual
Singular Combi Boiler - BTC 439002301 A (12.2021)
9.2 Control Board
1. Refer to 9.1 Preparation Step.
2. Loosen the connection terminals in the control board.
3. Loosen the 3 control board fi xing screws (circled in blue) assembled to the
chassis (Fig. 88).
Figure 88
4. Replace with a new control board and tighten the connection terminals.
5. Tighten the 3 control board fi xing screws. (Tighten the ground wire with the
control board top screw together.)
9.3 Sensor, Heating/Return
1. Refer to 9.1 Preparation Step.
2. Disconnect the temperature sensor terminal.
3. Replace with a new temperature sensor.
Figure 89
9.4 Sensor, DHW
1. Refer to 9.1 Preparation Step.
2. Disconnect the temperature sensor terminal.
3. Replace with a new temperature sensor.
Figure 90
9.5 Exhaust Temperature Sensor_T4 (Blue)
1. Refer to 9.1 Preparation Step.
2. Disconnect the temperature sensor terminal (Item 1).
3. Loosen the screw and remove the temperature sensor (Item 2).
Figure 91
1
2
4. Replace with a new temperature sensor and tighten the screw.