67
Fault code dis-
played
System characteristics
Cause
Measures
28
Regulates without flow tem-
perature sensor (low loss
header)
Lead break, system flow
temperature sensor
Check low loss header sensor (see
page 73).
If no low loss header sensor is
connected, set code 52:0.
30
Burner blocked
Short circuit, boiler water
temperature sensor
Check boiler water temperature
sensor (see page 73)
38
Burner blocked
Lead break, boiler water
temperature sensor
Check boiler water temperature
sensor (see page 73)
40
Mixer closes.
Short circuit, flow temper-
ature sensor, heating cir-
cuit 2 (with mixer)
Check flow temperature sensor
(see page 77)
44
Mixer closes.
Short circuit, flow temper-
ature sensor, heating cir-
cuit 3 (with mixer)
Check flow temperature sensor
(see page 77)
48
Mixer closes.
Lead break, flow tempera-
ture sensor, heating circuit
2 (with mixer)
Check flow temperature sensor
(see page 77)
4C
Mixer being closed
Lead break, flow tempera-
ture sensor, heating circuit
3 (with mixer)
Check flow temperature sensor
(see page 77)
50
No DHW heating by the boil-
er
Short circuit, cylinder tem-
perature sensor
Check sensors (see page 73)
58
No DHW heating by the boil-
er
Lead break, cylinder tem-
perature sensor
Check sensors (see page 73)
90
Control mode
Short circuit, temperature
sensor
/
Check sensor
/
on solar control
module.
91
Control mode
Short circuit, temperature
sensor
aÖ
Check sensor
aÖ
on solar control
module.
92
No solar DHW heating
Short circuit, collector
temperature sensor
Check temperature sensor
&
on
solar control module or sensor on
the Vitosolic.
93
Control mode
Short circuit, cylinder tem-
perature sensor
Check temperature sensor at con-
nection S3 on the Vitosolic.
94
No solar DHW heating
Short circuit, cylinder tem-
perature sensor
Check temperature sensor
%
on
solar control module or sensor on
the Vitosolic.
98
Control mode
Lead break, temperature
sensor
/
Check sensor
/
on solar control
module.
99
Control mode
Lead break, temperature
sensor
aÖ
Check sensor
aÖ
on solar control
module.
9A
No solar DHW heating
Lead break, collector tem-
perature sensor
Check temperature sensor
&
on
solar control module or sensor on
the Vitosolic.
9b
Control mode
Lead break, cylinder tem-
perature sensor
Check temperature sensor at con-
nection S3 on the Vitosolic.
9C
No solar DHW heating
Lead break, cylinder tem-
perature sensor
Check temperature sensor
%
on
solar control module or sensor on
the Vitosolic.
9E
Control mode
No or inadequate flow rate
in collector circuit, or tem-
perature limiter has re-
sponded.
Check solar circuit pump and solar
circuit. Acknowledge fault mes-
sage.
Troubleshooting
Fault codes
(cont.)
5686 293 GB
Diagnosis