Viessmann FB2B Installation And Service Instructions Manual page 105

Fault codes
(cont.)
Displayed System characteris-
fault code tics
51 No DHW heating
58 No DHW heating
59 No DHW heating
92 No DHW heating
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 in
case of insufficient
system pressure
Cause Measures
Short circuit, outlet Check sensors (see
temperature sen- page 117)
sor
Lead break, cylin- Check sensors (see
der temperature page 117)
sensor
Lead break, outlet Check sensors (see
temperature sen- page 117)
sor
Short circuit, col- Check sensor & to the
lector temperature
solar control module.
sensor (connection
to the solar control
module)
Short circuit, cylin- Check sensor % to the
der temperature
solar control module.
sensor (connection
to the solar control
module)
Lead break, collec- Check sensor & to the
tor temperature solar control module.
sensor (connection
to the solar control
module)
Lead break, cylin- Check sensor % to the
der temperature solar control module.
sensor (connection
to the solar control
module)
No flow rate in the Check solar circuit pump
collector circuit or and solar circuit. Acknowl-
flow rate too low, or edge fault message.
temperature limiter
has responded
Solar control mod- Replace solar control
ule fault module
System pressure Top up with water
too low
Troubleshooting
105