Fault" Is Displayed - Viessmann VITODENS Operating Instructions Manual

What to do if...

"Fault" is displayed

Cause
Heating system fault
and "Service" are displayed
ë
Cause
The time for a service, as specified by your heating
contractor, has arrived.
"Operation disabled" is displayed
Cause
The controls have been locked out.
"External hook-up" is displayed
Cause
The operating program set at the control unit has been
switched over by an external device, e.g. EA1 exten-
sion.
"External program" is displayed
Cause
The operating program set at the control unit has been
switched over by the Vitocom communication interface.
40
Remedy
Proceed as described on page 36.
Remedy
Proceed as described on page 35.
Remedy
Unlock the controls (see page 31).
Remedy
No action required. When the external changeover is
no longer present, the set operating program is active
again.
Remedy
You can change the operating program.