Dhw Production - Viessmann Vitodens 200 WB2 Series Technical Data Manual

Domestic Hot Water Production via
Instantaneous DHW Plate Heat Exchanger (Model WB2 6-24C)
The Vitodens 200 Combi boiler is equipped
with an electronically controlled
instantaneous DHW plate heat exchanger.
Technical Data DHW Plate Heat Exchanger
See page 5 in this manual for technical data.
ºF ºC
149 65
140 60
131 55
122 50
113 45
104 40
95 35
6 7
1.6 1.8
Draw rate at tap (mixed water)
DHW output temperature at the
Vitodens 200 boiler
DHW/DCW mixing zone
DHW output temperature at the mixing
valve
Restriction by flow limiter
IMPORTANT
Vitodens 200, WB2 6-24C combi boilers
cannot be connected to non-combi boilers in
the field. Proper DHW sizing, including
future DHW requirements, must be
performed before selecting combi boilers.
The comfort control function ensures that
the instantaneous DHW plate heat
exchanger is kept consistently at the
required temperature (115ºF / 46ºC - off,
108ºF / 42ºC - on).
8 9 10 11
2.1 2.4 2.6 2.9
The diagram on the left illustrates how the
DHW output temperature changes in relation
to the draw rate at the tap.
The DHW draw rate is restricted by means of
a flow limiter to 2.1 GPM/8 ltrs per min.
a temperature of 128 ºF/53 ºC.
If more water is required, domestic cold water
is added, resulting in a lower DHW output
temperature.
In the example to the left, demonstrating the
change in DHW output temperature based on
the addition of domestic cold water, a
domestic cold water input temperature of
50 °F/10°C is assumed.
12 13 14
ltr/min
3.1 3.4 3.7
GPM

DHW Production

This translates into immediate availability of
domestic hot water at any required
temperature level.
at
11