There Is No Hot Water; The Dhw Is Too Hot; Fault" Is Shown In The Display - Viessmann VITOLIGNO 300-H Operating Instructions For The System User

What to do if...

There is no hot water

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

The DHW is too hot

Cause
Control unit incorrectly set.
Sensor fault

"Fault" is shown in the display

Cause
Heating system fault
58
Remedy
Check the settings and correct if required:
■ DHW heating must be on (see
page 35)
■ DHW temperature (see page 35)
■ Time (see page 46)
■ Switching times (see page 36)
Check the settings and correct if required:
■ Set DHW temperature (see page 35)
■ Heating times for DHW heating (see
page 36)
If the heating times are OK: Check the
temperature of the DHW cylinder. If this
temperature is too low: Inform your local
heating contractor.
Check the heating times. If the pump is
running according to the times set in the
control unit: Inform your local heating
contractor.
Notify your local heating contractor.
Remedy
Check and correct the DHW temperature
if required (see page 35).
Inform your local heating contractor.
Remedy
Check the type of fault (see page 50) and
notify your local heating contractor.