Dhw Heating - Viessmann VITODENS 111-W Installation And Service Instructions Manual

Functions and operating conditions in...

DHW heating

Heating the DHW loading cylinder
from cold
The heating circuit pump is switched ON
and the 3-way diverter valve will be
changed over, if the cylinder tempera-
ture sensor captures a temperature
lower than the defaulted set value.
■ The cylinder loading pump is switched
ON if the boiler water temperature ≥
set cylinder temperature.
■ The burner is switched ON if the boiler
water temperature ≤ set cylinder tem-
perature, and the cylinder loading
pump is switched ON when the
required boiler water temperature is
reached.
The loading cylinder is heated up to the
set cylinder temperature. Heating stops
when the specified temperature has
been reached at the cylinder tempera-
ture sensor.
After loading has stopped, the cylinder
loading pump and the 3-way diverter
valve remain on for a further 30 s.
Reheating when DHW is drawn off
When DHW is drawn off, cold water
enters the lower section of the loading
cylinder.
The heating circuit pump is switched ON
and the 3-way diverter valve is changed
over, if the cylinder temperature sensor
captures a temperature lower than the
defaulted set value.
(cont.)
■ The cylinder loading pump is switched
ON if the boiler water temperature ≥
set cylinder temperature.
■ The burner is switched ON if the boiler
water temperature ≤ set cylinder tem-
perature, and the cylinder loading
pump is switched ON when the
required boiler water temperature is
reached.
DHW is regulated to the set temperature
via the outlet temperature sensor.
After the draw off process has ended the
loading cylinder continues to be heated
up, until the set DHW temperature has
been reached at the cylinder tempera-
ture sensor.
The cylinder loading pump and the
3-way diverter valve remain ON for a fur-
ther 30 s.
Control unit
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