Weather-Compensated Control Unit - Viessmann VITODENS 222-F Installation And Service Instructions Manual

Function description
Constant temperature control unit
Boosting when DHW is drawn off
When DHW is drawn off, cold water
enters at the bottom of the primary cyl-
inder.
The heating circuit pump is switched ON
and the three-way diverter valve is
changed over, if the cylinder tempera-
ture sensor recognises a temperature
lower than the set temperature.
■ The cylinder primary pump is switched
ON if the boiler water temperature ≥
set DHW temperature.
■ The burner is switched ON if the boiler
water temperature ≤ set DHW temper-
ature, and the cylinder primary pump
is switched ON when the required
boiler water temperature is reached.

Weather-compensated control unit

Boiler temperature
Heating
DHW
Solar energy
Information
Select with
114
(cont.)
The DHW is controlled to the specified
temperature via the cylinder temperature
sensor.
The primary cylinder continues to be
heated up after the draw off process has
terminated, until the set DHW tempera-
ture has been reached at the cylinder
temperature sensor.
The cylinder primary pump and the
three-way diverter valve remain ON for a
further 30 s.
48°C