19
Fault codes
Service instructions for the heat generator or the
Vitotronic control unit
Errors without fault code display
Fault
Cause
Remedy
Solar yield is too low.
Temperature sensors have
been interchanged.
Check temperature sensor connections.
Air in the solar circuit
Vent the solar circuit. Check flow rate.
Flow rate is too low.
■
Check flow rate.
■
Check connection of output
sF
(see
page 20).
Check coding address "02".
■
Check hydraulic connections.
■
Ensure check valves are operating correctly.
Incorrect circulation
Check the system characteristics (see
page 21).
Solar circuit pump not running
or runs constantly.
Temperature sensors have
been interchanged.
Check temperature sensor connections.
Check coding address "20".
Solar circuit pump is faulty or
incorrectly connected.
Check solar circuit pump connection (see
page 20).
Check coding address "02".
Carry out a relay/actuator test (see the service
instructions for the heat generator or the
Vitotronic control unit).
Output
sS
not switched or per-
manently switched.
Incorrect function configured.
Check setting of coding address "20".
SDIO/SM1A electronics mod-
ule is faulty.
Check connection of output
sS
(see page 20).
Carry out a relay/actuator test (see the service
instructions for the heat generator or the
Vitotronic control unit).
Solar control unit is not opera-
tional.
MCB F1 has responded.
Check fuse F1 (see page 32).
Disconnect consumers. Connect again in se-
quence. During this, observe the behaviour of
MCB F1.
Repairs
Check function of connected components by means of
a relay/actuator test:
Service instructions for the heat generator or the
Vitotronic control unit
Troubleshooting
Faults displayed with a fault code
6131981
Diagnosis
