A3 Error (Abnormal Operation: Pump) - Bosch Singular 4000 Service Manual

8.2 A3 Error (Abnormal Operation: Pump)

Error
Abnormal Pump Operation
Checkpoint
Table 25
Figure 10
Singular Combi Boiler - BTC 439002301 A (12.2021)
Description
 Determine whether the pump is in operation when the boiler operation signal is activated
 Before operating the pump, check the change in the pressure sensor before and after to see whether there are any
problems in the operation of the pump.
 Check the assembly of the pump connector
 Check the operation voltage of the pump
Color: White – Black
—
 Check for any clogging of heating water pipes
Check the assembly of the
control board and the pump
connector and reassemble
them. Check the operation
of the pump and the flow of
heating water.
Power ON / Operation
Check the
pump input
voltage
Yes
Whether
the pump is
running
Yes
Check for any
clogging of
heating pipes
Yes
Replace the control board
No
Replace the control board
White-Black: AC 100 120 V
No
Replace the pump
No Check for any clogging of
heating pipes
Service Manual
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