Viessmann VITODENS 111-W Technical Manual page 51

Design information
In existing installations (modernisation projects), the risk of electro-
lytic corrosion is low, since a protective layer will have formed on the
inside of the pipes.
If DHW is to be drawn simultaneously from several points, we rec-
ommend the installation of a separate DHW cylinder in conjunction
with the gas condensing boiler (see "Decision-making aids regarding
DHW heating").
Cold water installation of Vitodens 100-W gas condensing combi boiler
B
A
WW KW
HV GA HR
D
Visible drain pipe outlet
A
Safety valve
B
Non-return valve
C
Drain outlet
D
Shut-off valve
E
Cold water
F
GA Gas connection
HR Heating return
HV Heating flow
KW Cold water
WW DHW
A safety valve to DIN 1988 is only required if the mains water supply
pressure exceeds 10 bar (1 MPa) and no DHW pressure reducing
valve is installed (to DIN 4753).
VITODENS
(cont.)
C D E F
Safety assembly
For a water hardness of 20 °dH (3,5 mol/m
mend the use of a water treatment system in the cold water line
when heating DHW.
Install a safety valve if the cold water supply is equipped with a non-
return valve. In addition remove the toggle from the cold water shut
off-valve.
Non-return valves are commonly found in pressure reducers and
combined shut-off and non-return valves.
Shock arrestor
Ø 86
R½"
If the pipework to which the Vitodens is connected also supplies
draw-off points at which water hammers may occur (e.g. pressure
washers, washing machines or dishwashers): Install shock arrestors
near the source of the water hammer (recommended).
Flexofit S made by Flamco-Flexcon
or
Reflex made by Winkelmann + Pannhoff GmbH
(available from your local dealer).
3 ) and higher, we recom-
VIESMANN
51
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