Bosch ZBR16-3A, Installation And Service Instructions Manual

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Faults | 91
6 720 643 068 (2011/06) Copyright (optional information)
16.2 Faults that are shown on the display
Display Description Elimination
A7 DHW temperature sensor defective.
B
Check temperature sensor and leads for interruptions or
shorts, and replace if defective.
B
Insert code plug correctly; replace if defective.
A8 Communication fault.
B
Check BUS communications wiring, replace if defective.
B
Check control, replace if defective.
Ad DHW tank temperature not detected.
The DHW tank temperature sensor was
recognized before the connection was
lost.
B
Check DHW tank temperature sensor and connecting lead,
replace if defective.
B
Reset the boiler to the factory default settings (
Æ
service
function 8.E), reset the IPM 2
(if installed)
to the factory
default settings and carry out the automatic system configu-
ration.
b1 Code plug not detected.
B
Insert code plug correctly; replace if defective.
b2/b3/
b4/b5/
b6
Internal data error.
B
Reset boiler to factory default setting (
Æ
service function
8.E).
b7 Fault in the burner controls.
B
Reset boiler to factory to default setting (
Æ
service function
8.E).
C6 Fan not running.
B
Check fan leads and fan, replace if defective.
CC Outdoor temperature sensor not recog-
nized.
B
Check outdoor temperature sensor and leads for interrup-
tions, replace if defective.
B
Verify the outdoor temperature sensor is connected to termi-
nals A and F.
d3 Temperature high limit defective.
External guard has tripped.
Temperature limiter locked out.
B
Check temperature sensor and leads for interruptions or
shorts, and replace if defective.
B
Temperature guard TB1 has tripped. Check if jumper across
8-9 or PR-P0 is missing.
B
Reset external temperature limiter (if installed).
B
Reset LWCO (if installed).
d5 External supply temperature sensor defec-
tive (low-loss header).
The external supply temperature sensor
was recognized on the BUS and then
reconnected to the appropriate terminal.
B
Check temperature sensor and leads for interruptions or
shorts, and replace if defective.
B
Check whether only one temperature sensor is connected;
otherwise remove second temperature sensor.
B
Reset the boiler to the factory default settings (
Æ
service
function 8.E), reset the IPM 2 (if installed) to the factory
default settings and carry out the automatic system configu-
ration.
Tab. 37 Faults shown on the display