Viessmann vitodens Technical Manual page 61

DHW connection on Vitodens 200 and 300 gas fired combination boiler
For the DHW connection, connection sets
for installation on finished walls or for
installation on unfinished walls are
available as accessories. The integral
standby instantaneous water heater
provides direct DHW heating.
Cold water installation
B
A
WW
KW
HV GA HR
D
Anti-water hammer device
VITODENS
2.5 Connections on the gas and the water side
Note when using this feature in
conjunction with galvanised pipes, that
the standby instantaneous water heater is
designed as stainless steel plate heat
exchanger with copper solder joints.
In existing installations (modernisation
projects), the danger of electrolytic
corrosion is low, since a protective layer
will have been formed on the inside of
pipes.
A Visible drain outlet
B Safety valve
C D E F
C Non-return valve
D Drain
E Shut-off valve
Safety equipment
F Cold water
GA Gas connection
HR Heating return
HV Heating flow
KW Cold water
WW Hot water
If DHW should be drawn simultaneously
from several points, we would
recommend the installation of a separate
DHW cylinder in conjunction with the gas
fired boiler.
From a water hardness of 20º dH and
higher, we recommend the use of a water
treatment system in the cold water supply
when considering DHW heating.
A safety valve to DIN 1988 must only be
installed if the mains drinking water
supply pressure is higher than10 bar and
no pressure reducer is used (to DIN 4753).
A safety valve must be installed if the
cold water supply is equipped with a
non-return valve. In addition, the toggle
must be fitted to the cold water shut
off-valve.
Non-return valves may also be found in
pressure reducers and combined
free-flow valves with non-return valves.
We recommend the installation of an
anti-water hammer device near pressure
shock generators, if the pipework to
which Vitodens is connected comprises
taps where water hammers may be
created (e.g. pressure washers, washing
or dishwashing machines).
Flexofit S made by Flamco Flexcon
or
reflex made by Winkelmann +
Pannhoff GmbH
(available from your local dealer).
200
300
2
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