Av Air Vent - Viessmann Vitodens 200 WB2 Series Technical Data Manual

System Layout 4
Vitodens 200 (up to model WB2 8-32) with...
– DHW storage tank
– two heating circuits with a mixing valve
PRV
TPV
S
Y
S
Important:
Please note location of expansion tank
Installation of different heating circuits...
H radiator heating circuit
H underfloor heating circuit with 3-way
mixing valve (low temperature circuit)
H DHW production
...with the following flow conditions
1. The total flow rate of the two heating
circuits is greater than the maximum
possible flow rate of the Vitodens 200 (see
following table).
Model No. Max. flow rate
(GPM/ltr/h)
Vitodens 200,
WB2 6-24C 6.2/1400
WB2 6-24 6.2/1400
WB2 8-32 7.0/1600
The use of a low-loss header is therefore
recommended.
The low-loss header is available as
accessory part.
See page 34 in this manual for details on
the low-loss header.
AV
M
~
O
The 3-way mixing valve, built-in to achieve
the low temperature level of the underfloor
heating circuit, is controlled by an accessory
kit for a heating circuit with mixing valve.
The circulation pump built into the Vitodens
200 boiler supplies the heating circuit up to
the low-loss header.
The underfloor and radiator heating circuits
are supplied by circulation pumps installed
on site which are controlled by the
accessory kit or the Vitotronic 050/
Dekamatik-HK1 control.
If more than two heating circuits with
mixing valves are to be connected, they can
be controlled by the Vitocontrol.
Contact your local Viessmann Technical
Sales Representative for details.
Upon a call for DHW, the built-in diverting
solenoid valve is energized. The boiler hot
water is diverted to the DHW loop at
maximum pump rotational speed (no
variable speed pump operation during DHW
production). Once the DHW tank is
satisfied, the built-in diverting solenoid valve
is de-energized and heating operation
resumes.

AV Air vent

PRV Pressure relief valve
TPV Temperature and pressure relief
valve
P
Vitodens 200 gas-fired condensing
boiler with programming unit for
weather-responsive operation with
2-wire BUS expansion module
Outdoor temperature sensor
Remote control for programming unit
Underfloor heating circuit
Radiator heating circuit
Heating circuit pump (field supplied)
Mixing valve temperature sensor
Accessory kit for a heating circuit
with mixing valve
I
Vitotronic 050/Dekamatik-HK1 control
M
~
with communication module
I DHW storage tank
DHW tank temperature sensor
Expansion tank
Low-loss header
O
Viessmann temperature sensor for
low-loss header
P
Vitotrol 200 remote control
R
Optional purge tee (field supplied) for
easier air removal
S
DHW supply and return piping
IMPORTANT
DHW supply and return piping between
boiler DHW connections and the Viessmann
DHW tank connections S , shall be a
minimum of 1" nominal pipe diameter
(irrespective of the ¾" DHW connection
outlet sizes provided on the boiler and the
DHW tank). This will ensure the residual
head of the built-in pump is fully utilized to
overcome the resistance of the DHW heat
exchanger coil and to provide sufficient
water flow to the boiler heat exchanger.
In non-Viessmann DHW tank applications,
perform, in addition to the above, accurate
calculations for DHW tank coil pressure drop
versus boiler pump residual head to ensure
sufficient water flow to the boiler heat
exchanger. Failure to heed the above
instructions may cause boiler short-cycling
and inadequate DHW supply.
Installation Examples
41