Faults That Are Shown On The Display - Bosch ZBR16-3A Installation And Service Instructions Manual

16.2 Faults that are shown on the display

Display Description
A7 DHW temperature sensor defective.
A8 Communication fault.
Ad DHW tank temperature not detected.
The DHW tank temperature sensor was
recognized before the connection was
lost.
b1 Code plug not detected.
b2/b3/ Internal data error.
b4/b5/
b6
b7 Fault in the burner controls.
C6 Fan not running.
CC Outdoor temperature sensor not recog-
nized.
d3 Temperature high limit defective.
External guard has tripped.
Temperature limiter locked out.
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.
Tab. 37 Faults shown on the display
Copyright (optional information)
Elimination
B Check temperature sensor and leads for interruptions or
shorts, and replace if defective.
B Insert code plug correctly; replace if defective.
B Check BUS communications wiring, replace if defective.
B Check control, replace if defective.
B Check DHW tank temperature sensor and connecting lead,
replace if defective.
B Reset the boiler to the factory default settings (
function 8.E), reset the IPM 2
default settings and carry out the automatic system configu-
ration.
B Insert code plug correctly; replace if defective.
B Reset boiler to factory default setting (
8.E).
B Reset boiler to factory to default setting (
8.E).
B Check fan leads and fan, replace if defective.
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.
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).
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 (
function 8.E), reset the IPM 2 (if installed) to the factory
default settings and carry out the automatic system configu-
ration.
Faults | 91
service
to the factory
(if installed)
service function
service function
service
6 720 643 068 (2011/06)