104
Dis-
played
fault
code
Const.
Weath.-
comp.
System char-
acteristics
Cause
Measures
10
X
X
Regulates as if
the outside
temperature
were 0 °C
Short circuit,
outside tem-
perature sen-
sor
Check the outside
temperature sen-
sor (see
page 116)
18
X
X
Regulates as if
the outside
temperature
were 0 °C
Lead break,
outside tem-
perature sen-
sor
Check the outside
temperature sen-
sor (see
page 116)
20
X
X
Regulates with-
out flow tem-
perature sen-
sor (low loss
header)
Short circuit,
system flow
temperature
sensor
Check the low loss
header sensor (see
page 118)
28
X
X
Regulates with-
out flow tem-
perature sen-
sor (low loss
header)
Lead break,
system flow
temperature
sensor
Check the low loss
header sensor (see
page 118)
30
X
X
Burner blocked Short circuit,
boiler water
temperature
sensor
Check the boiler
water temperature
sensor (see
page 118)
38
X
X
Burner blocked Lead break,
boiler water
temperature
sensor
Check the boiler
water temperature
sensor (see
page 118)
40
X
Mixer closes
Short circuit,
flow tempera-
ture sensor,
heating circuit
2 (with mixer)
Check flow temper-
ature sensor
44
X
Mixer closes
Short circuit,
flow tempera-
ture sensor,
heating circuit
3 (with mixer)
Check flow temper-
ature sensor
Troubleshooting
Fault codes
5457 552 GB