Faults That Are Shown On The Display - Bosch Greenstar FS Series Installation And Maintenance Instructions For Contractors

17.2

Faults that are shown on the display

Display Description
A7 DHW temperature sensor defective. ▶ Check temperature sensor and leads for interruptions or shorts, and replace if defective.
A8 Communication fault.
Ad DHW tank temperature not detected.
The DHW tank temperature sensor as
recognized before the connection
was lost.
b1 Code plug not detected.
b2/ Internal data error.
b3/
b4/
b5/
b6
b7 Fault in the burner controls.
C6 Fan not running.
CC Outdoor temperature sensor not
recognized.
d3 Temperature high limit defective.
External guard has tripped.
Temperature limiter locked out.
d5 External supply temperature sensor
defective (low-loss header).
The external supply temperature
sensor was recognized on the BUS
and then reconnected to the
appropriate terminal.
E2 Supply temperature sensor
defective.
E3 Additional supply temperature
sensor defective.
E9 Heat exchanger safety high limit or
flue gas temperature limiter has
tripped.
Greenstar FS/Combi FS – 6 720 810 590 (2020/04)
Elimination
▶ Insert code plug correctly; replace if defective.
▶ Check BUS communications wiring, replace if defective.
▶ Check control, replace if defective.
▶ Check DHW tank temperature sensor and connecting lead, replace if defective.
▶ Reset the boiler to the factory default settings (service function 8.E), reset the IPM 2 (if
installed) to the factory default settings and carry out the automatic system configuration.
▶ Insert code plug correctly; replace if defective.
▶ Reset boiler to factory default setting ( service function 8.E).
▶ Reset boiler to factory to default setting ( service function 8.E).
▶ Check fan leads and fan, replace if defective.
▶ Check outdoor temperature sensor and leads for interruptions, replace if defective.
▶ Verify the outdoor temperature sensor is connected to 3 (Out Sen) on the terminal block in the
low voltage junction box.
▶ Check temperature sensor and leads for interruptions or shorts, and replace if defective.
▶ Temperature guard TB1 has tripped. Check if jumper across 8-9 or PR-P0 is missing.
▶ Reset external temperature limiter (if installed). Reset LWCO (if installed).
▶ Check temperature sensor and leads for interruptions or shorts, and replace if defective.
▶ Check whether only one temperature sensor is connected; otherwise remove second
temperature sensor.
▶ Reset the boiler to the factory default settings ( service function 8.E), reset the IPM 2 (if
installed) to the factory default settings and carry out the automatic system configuration.
▶ Check temperature sensor and leads for interruptions or shorts, and replace if defective.
▶ Check temperature sensor and leads for interruptions or shorts, and replace if defective.
▶ Check flue gas safety high limit and leads for interruptions or shorts, and replace if defective.
▶ Check heat exchanger safety high limit and leads for interruptions or shorts, and replace if
defective.
▶ Check the operating pressure.
▶ Check temperature limit; replace if defective.
▶ Check pump capacitor; replace pump if defective.
▶ Check PCB fuse, replace if blown (6.3 A fuse according to IEC default).
▶ Purge the appliance
▶ Check heat exchanger on the DHW side; replace if clogged.
Faults
75