Viessmann VITODENS 242-F Installation And Service Instructions Manual page 127

Fault codes
(cont.)
Displayed System characteris-
fault code tics
94 No solar DHW heat-
ing.
9A No solar DHW heat-
ing.
9C No solar DHW heat-
ing.
9E Control mode
9F Control mode
A2 Emergency mode
where system pres-
sure is too low
Cause
Short circuit, cylin-
der temperature
sensor; tempera-
ture sensor %
connection on the
solar control mod-
ule.
Lead break, collec-
tor temperature
sensor; tempera-
ture sensor &
connection on the
solar control mod-
ule.
Lead break, cylin-
der temperature
sensor; tempera-
ture sensor %
connection on the
solar control mod-
ule.
No flow rate in so-
lar circuit or flow
rate too low, or
temperature limiter
has responded.
Solar control mod-
ule fault
System pressure
too low
Troubleshooting
Measures
Check cylinder tempera-
ture sensor (see
page 140)
Check collector tempera-
ture sensor (see
page 140)
Check cylinder tempera-
ture sensor (see
page 140)
Check solar circuit.
Acknowledge fault mes-
sage (see separate instal-
lation and service instruc-
tions).
Replace solar control
module
Top up with water
127