Viessmann Vitocal 222-G User Manual page 5

Vitocal 222-G/242-G/333-G/333-G NC/343-G
2.2 Vitocal 222/242/333/343-G, one heating circuit without mixer and DHW heating (for
Vitocal 242/343-G also solar)
2
ID: 4605087_1304_05
Note
DHW heating with solar backup is only possible with the
Vitocal 242/343-G.
A system volume of at least 3 litres per kW of heat pump output is
required.
Application range
Detached house with underfloor heating system.
Main components
■ Vitocal 222/242/333/343-G with integral DHW cylinder and
Vitotronic 200, type WO1C
■ Heating circuit distributor with heating circuit without mixer
■ Solar thermal system (option, only with the Vitocal 242/343-G)
Requirements
The minimum flow rate of heat pump 1 is safeguarded by overflow
valve oW and the integral secondary pump. In these heating systems,
install an overflow valve at the heating circuit distributor of the under-
floor heating system. This safeguards a minimum volume of circulating
water, even in sealed heating circuits.
Central heating by heat pump
Heat pump 1 and the integral primary pump start if the actual tem-
perature captured by the return temperature sensor in the secondary
circuit is lower than the temperature set at control unit 2 or for DHW
heating.
Required parameter settings
ID: 4605087_1304_05
Parameter
7000
7A00
C002
VIESMANN
10
Value Function
2 With heating circuit A1/HC1, DHW cylinder (delivered condition)
3 Solar control module, type SM1
2 Variable speed solar circuit pump with PWM activation
(cont.)
Heat pump 1 supplies the heating circuit with heat. Control unit 2
of heat pump 1 regulates the heating water flow temperature and
thereby the heating circuit. The integral secondary pump delivers the
heating water via a 3-way diverter valve either to the heating circuit or
to the integral DHW cylinder.
Opening and closing the valves of the underfloor heating distributor
regulates the flow rate within the heating circuit. Heat pump 1 and
the secondary pump are switched off once the actual return tempera-
ture at the return temperature sensor exceeds the temperature set at
the control unit.
DHW heating by heat pump
In the delivered condition, DHW heating by heat pump 1 is given
priority over the heating circuit 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 and, in the case of
the Vitocal 242/343-G, the cylinder loading pump.
The control unit 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" if the actual temperature at the cyl-
inder temperature sensor exceeds the value set at the control unit.
The flow temperature can be raised up to 60 °C via integral instanta-
neous heating water heater 4.
DHW heating with solar backup (only for Vitocal 242/343-G)
The DHW cylinder will be heated by the solar collector if the temper-
ature differential between collector temperature sensor rR and the
integral lower cylinder temperature sensor exceeds the temperature
differential set at the control unit. For this, the heat pump control unit
controls solar circuit pump rE which is integrated into Solar-Divicon
rW.
The control unit stops solar circuit pump rE again if the temperature
falls below the temperature differential.
System examples