There Is No Hot Water; The Dhw Is Too Hot; Fault" Is Shown On The Display; Solar Risk Of Overheating" Appears On The Display - Viessmann VITOLIGNO 300-C Operating Instructions Manual

Vitoligno 300-C Operating

There is No Hot Water

Cause
Control unit incorrectly set.
DHW tank is cold.
The DHW tank pump is not running.
Mixing valve faulty

The DHW is Too Hot

Cause
Control unit incorrectly set.
Sensor fault

"Fault" is Shown on the Display

Cause
Heating system fault

"Solar Risk of Overheating" Appears on the Display

Cause
No more heat can be transferred from a connected
solar thermal system (e.g. solar tank is full) and the
collectors are overheating.
Remedy
Check the settings and correct if required:
DHW heating must be on (see page 28)

DHW temperature (see page 28)

Time (see page 37)

Switching times (see page 29)

Check the DHW heating times (see page 29)
Check the set DHW temperature (see page 28)
If the heating times are OK: Check the temperature of
the DHW tank.
If it is too low: Notify your heating contractor.
Check the heating times. If the pump is supposed to be
running according to the times set in the control unit:
Notify your heating contractor.
Notify your heating contractor.
Remedy
Check and correct the DHW temperature if required
(see page 28).
Notify your heating contractor.
Remedy
Check the type of fault (see page 39) and notify your
heating contractor.
Remedy
This message is for information only and disappears
once the solar thermal system has cooled down again.
Troubleshooting
43