39
Troubleshooting
Faults which are displayed at the programming unit
(cont.)
Fault
code
System
characteristics
Cause
Remedy
9f
Control mode
Only solar control
unit fault codes will
be displayed
Fault
Solar control unit;
displayed if a fault
without fault code
occurs at the solar
control unit
Check solar control
unit
b0
Control mode
Short circuit
Flue gas temperature
sensor
Check flue gas
temperature sensor
(see page62)
b1
Communication fault
Programming unit
Check connections
and replace
programming unit, if
necessary
b4
Emissions test mode
Internal fault
Check supplementary
PCB
b5
Control mode
Internal fault
Check supplementary
PCB
b6
Constant mode
Invalid hardware
recognised
Check main PCB
b7
The boiler is
regulated by the
control thermostat
Boiler coding card
fault
Plug in boiler coding
card or replace, if
faulty
b8
Control mode
Lead broken
Flue gas temperature
sensor
Check flue gas
temperature sensor
(see page 62).
Without flue gas
temperature sensor:
Set code 1F:0
b9
Internal fault
Acknowledge fault,
repeat data input
5862700GB