Fault
code
Sub
code
Cause
Appliance
action
User action
E155
E2000
Touchscreen fault;
general fault message
Fault codes only
visible when
using service
tool
Check wiring to touchscreen; replace wiring
if damaged; replace touchscreen if fault still occurs replace
UWA2-B
Fault is automatically reset when voltage is again put back on
appliance
E120
E2100
EBus fault; general fault
message
Air Control and
other accessories
connected to
eBus do not
work. Appliance
is working
Check wiring to accessories/ Air Control
Check accessories/ Air Control and replace if defective
If there is still a fault after this: Take voltage from appliance
and replace basic pcb UWA2-B
E121
E2200
external Bus general fault
message
Air Control and
other accessories
do not work.
Appliance is
working
Check wiring to accessories/ Air Control
Check accessories/ Air Control and replace if defective
If there is still a fault after this: Take voltage from appliance
and replace basic pcb UWA2-B
E122
E2300
Internal ModBus fault;
general fault message
Appliance goes
to standby
Check wiring and connections to UWA2-B and the fans
Replace cable harness if damaged; Then exchange UWA2B,
exhaust fan and supply fan
E123
E2400
External ModBus fault;
general fault message
Operation via
Modbus does not
work
Check cabling of accessories; replace if damaged
Check accessories; replace if defective
If fault still occurs: Take voltage from appliance and replace
UWA2-B basic pcb
E124
E2500
USB port general fault
message
USB interface not
usable
Replace USB accessory
If the fault is not remedied after this: take the voltage from
the appliance and replace UWA2-B basic pcb
E170
E2600
One or more CO
2
sensor(en) defective;
general fault message
Appliance is
working; no CO
2
regulation
Check cabling and CO
2
sensor(s); replace if damaged
Check CO
2
sensor(s); replace if defective
E171
E2700
External preheater or
fuse defective; general
fault message
No preheater /
comfort control
responds
differently
Uncouple preheater and check preheater fuse; replace fuse if
defective
Has the fault not yet been remedied:
Replace external preheater
Put voltage back on appliance
Fault has automatically been reset
E172
E2800
External postheater or
fuse defective; general
fault message
No postheater /
comfort control
responds
differently
Uncouple postheater and check postheater fuse; replace fuse
if defective
Has the fault not yet been remedied:
Replace external postheater
Put voltage back on appliance
Fault has automatically been reset
Ubiflux Vigor W325 615743-G
