Viessmann Vitocal 222-G User Manual page 150

Vitocal 200-S/222-S/242-S
5.6 Vitocal 222-S, type AWT-AC, one heating circuit without mixer, with DHW heating
ID: 4605416_1304_03
Application range
Detached houses with standard utilisation characteristics, underfloor
heating system. Size the DHW cylinder in accordance with current
standards and requirements.
Main components
■ Vitocal 222-S, type AWT-AC, with Vitotronic 200 control unit, type
WO1C
■ One heating circuit without mixer
■ Integral DHW cylinder
Requirements
The minimum flow rate of the heat pump must be safeguarded by sec-
ondary pump 6 and overflow valve oW. The heating line and overflow
valve must be matched up hydraulically.
Central heating by heat pump
The heat pump starts if the actual temperature captured by the flow
temperature sensor in heat pump internal unit 1 is lower than the set
temperature selected at control unit 2. Heat pump 1/wO supplies
heating circuit oP with heat. Control unit 2 in heat pump internal unit
1 regulates the heating water flow temperature and thereby the heat-
ing circuit.
Required parameter settings
ID: 4605416_1304_03
Parameter
7000
System examples
(cont.)
Value Function
2 With heating circuit A1/HC1, DHW cylinder (delivered condition)
Secondary pump 6 in internal unit 1 delivers the heating water via
3-way diverter valve 5 either to DHW cylinder eP or to heating circuit
oP. Opening and closing the valves at the underfloor heating system
distributor regulates the flow rate within the heating circuit. Once the
actual flow temperature value at the flow temperature sensor inside
internal unit 1 exceeds the set temperature selected at the control
unit, the heat pump and secondary pump 6 are switched off.
DHW heating by heat pump
In the delivered condition, DHW heating by heat pump 1/wO is given
priority over the heating circuits and takes precedence at night.
The heat demand is issued via the integral cylinder temperature sensor
and the control unit, which controls the integral secondary pump in
conjunction with the integral 3-way diverter valve.
The heat pump raises the flow temperature to the value required for
DHW heating.
The control unit switches the heating flow to the heating circuit via 3-
way diverter valve "Heating/DHW" 5 if the actual temperature at the
upper cylinder temperature sensor exceeds the value set at the control
unit.
The flow temperature can be raised > 60 °C via integral instantaneous
heating water heater 4.
5
VIESMANN
155