Viessmann Vitoligno 300-P Service Instructions For Contractors page 80

Troubleshooting
Fault display
Fault code System characteris-
on the dis- tics
play
93 Solar circuit pump
switched OFF; no cyl-
inder heating through
the solar thermal sys-
tem.
Collector frost protec-
tion function starts, if
enabled and if
required
94 Solar circuit pump
switched OFF; no cyl-
inder heating through
the solar thermal sys-
tem.
Collector frost protec-
tion function starts, if
enabled and if
required
9A Solar circuit pump
switched OFF; no cyl-
inder heating through
the solar thermal sys-
tem.
Collector frost protec-
tion function starts, if
enabled and if
required
9B Solar circuit pump
switched OFF; no cyl-
inder heating through
the solar thermal sys-
tem.
Collector frost protec-
tion function starts, if
enabled and if
required
80
(cont.)
Cause
Short circuit, tem-
perature sensor
External Vitosolic
solar control unit:
Connection to S3
Short circuit, cylin-
der temperature
sensor
External Vitosolic
solar control unit:
Connection to S2
Collector tempera-
ture sensor lead
broken
External Vitosolic
solar control unit:
Connection to S1
Break, tempera-
ture sensor
External Vitosolic
solar control unit:
Connection to S3
Measures
Check temperature sen-
sor (see page 85)
Check the cylinder tem-
perature sensor (see
page 85)
Check collector tempera-
ture sensor (see
page 85)
Check temperature sen-
sor (see page 85)