Viessmann VITOCROSSAL Service Instructions Manual page 69

Fault codes
(cont.)
Fault code dis- System characteristics
played
48 Mixer is being closed.
4C Mixer is being closed.
50 No DHW heating
58 No DHW heating
90 Control mode
91 Control mode
92 No solar DHW heating
93 Control mode
94 No solar DHW heating
98 Control mode
99 Control mode
9A No solar DHW heating
9B Control mode
9C No solar DHW heating
9E Control mode
9F Control mode
A3 Burner blocked.
A4 Control mode
A7 Control mode as per deliv-
ered condition
B0 Burner blocked
Cause
Lead break, flow tempera-
ture sensor, heating circuit
2 (with mixer)
Lead break, flow tempera-
ture sensor, heating circuit
3 (with mixer)
Short circuit, cylinder tem-
perature sensor
Lead break, cylinder tem-
perature sensor
Short circuit, temperature
sensor
/
Short circuit, temperature
sensor
aÖ
Short circuit, collector
temperature sensor
Short circuit, cylinder tem-
perature sensor
Short circuit, cylinder tem-
perature sensor
Lead break, temperature
sensor
/
Lead break, temperature
sensor
aÖ
Lead break, collector tem-
perature sensor
Lead break, cylinder tem-
perature sensor
Lead break, cylinder tem-
perature sensor
No or inadequate flow rate
in collector circuit, or tem-
perature limiter has re-
sponded.
Solar control module or
Vitosolic fault
Flue gas temperature sen-
sor incorrectly positioned.
Max. system pressure ex-
ceeded
Programming unit faulty
Short circuit, flue gas tem-
perature sensor
Troubleshooting
Measures
Check flow temperature sensor.
Check flow temperature sensor.
Check sensors (see page 76).
Check sensors (see page 76).
Check sensor on solar control
/
module.
Check sensor on solar control
aÖ
module.
Check temperature sensor
solar control module or sensor on
the Vitosolic.
Check temperature sensor at ter-
minal S3 on the Vitosolic 100.
Check temperature sensor
solar control module or sensor on
the Vitosolic.
Check sensor / on solar control
module.
Check sensor aÖ on solar control
module.
Check temperature sensor
solar control module or sensor on
the Vitosolic.
Check temperature sensor at ter-
minal S3 on the Vitosolic 100.
Check temperature sensor
solar control module or sensor on
the Vitosolic.
Check solar circuit pump and solar
circuit. Acknowledge fault mes-
sage.
Replace solar control module or Vi-
tosolic.
Fit flue gas temperature sensor
correctly. See page 77
Check system pressure: Max.
3 bar (0.3 MPa)
Check the function and sizing of
the diaphragm expansion vessel.
Vent the heating system.
Replace the programming unit.
Check flue gas temperature sen-
sor.
on
&
% on
on
&
on
%
69