33
Maintenance and care
: Trouble shooting
en
A B C
Error
code Fault
Possible cause
Action
required
Reset
3 R
0
E 3
By-pass damper
does not close as
expected
Switch
position A:
Bypass is closed,
but supply
temperature
is lower than
expected
Check if bypass is
enabled in PC-Tool
Automatic reset
if efficiency is
high enough
for 30 seconds
Check if bypass is
blocked
Check mechani-
cal connection
between bypass ac-
tuator and bypass
valve
Switch
position B:
Bypass is closed,
but exhaust
temperature
is higher than
expected
Check electric con-
nection between
controller and
bypass
Check controller
output
By-pass damper
Reduced heat
recovery due to
low extract flow
Dirty extract air
filter
Change filters
Automatic reset
if efficiency is
high enough
for 30 seconds
Poor balancing
of the air flows
Adjust the system
A bathroom
extract fan is
creating under-
pressure in the
house
Remove the extract
fan from the bath-
room
and instead
connect the extract
air from the bath-
room
to the ventilation
system
A kitchen
extract fan is
creating under-
pressure in the
house
Create heated
replacement
air for the
extraction hood. If
not possible open a
window/door while
the extraction hood
is running
A stove fan is
creating under-
pressure in the
house
Contact supplier
of chimney/stove
to secure safety
precautions
3 R
0
E3
Bypass is closed,
but supply tem-
perature is lower
than expected
Flows are not
balanced. There
are much more
extract air than
supply air
Dirty supply air
filter
Change filters
Poor balancing
of the air flows
Adjust the system
