Viessmann VITODENS 111-W Technical Manual page 53

Design information
Cold water installation, separate DHW cylinder and loading cylinder of the Vitodens 111-W
Example:
DHW cylinder installed below (120 or 150 l) with safety assembly to
DIN 1988
C
P
2
1 3
A 0 4
bar
r
A DHW
B Safety valve
Included in the standard delivery of the installation aid for the
Vitodens 111-W
C Visible discharge pipe outlet point
D Cold water
E Drain outlet
F Shut-off valve
G Flow regulating valve (installation recommended)
Safety valve
The safety valve must be installed.
Drinking water filter
According to DIN 1988-2, a drinking water filter should be installed in
systems with metal pipework. Viessmann also recommends the
installation of a drinking water filter when using plastic pipes to
DIN 1988 to prevent contaminants entering the DHW system.
DHW circulation
DHW circulation pipes increase DHW convenience and reduce water
consumption. These advantages result from the immediate availabil-
ity of DHW at the tap/draw-off point.
However, poor thermal insulation of the DHW circulation pipe can
lead to substantial heat losses.
From a line length of 7 m we recommend providing appropriate
thermal insulation for the DHW circulation in accordance with the
Energy Saving Ordinance [Germany]. This specifies that the DHW
circulation pipe should, in accordance with the Energy Saving Ordi-
nance, include a circulation pump, a check valve and a time switch
for shutting down DHW circulation during the night.
VITODENS
(cont.)
O
B
F G H KE F
Safety assembly to DIN 1988
E
F E L M
D
H Pressure gauge connection
K Non-return valve
L Drinking water filter
M Pressure reducer to DIN 1988-2, Dec. 1988 issue
N Non-return valve/pipe separator
O Standard delivery of the safety assembly offered as an acces-
sory (for separate DHW cylinders only)
P Diaphragm expansion vessel, suitable for potable water
We recommend you install the safety valve higher than the top edge
of the cylinder. This protects the safety valve against contamination,
scaling and high temperatures. It also means that the DHW cylinder
does not need to be drained when working on the safety valve.
F N D
VIESMANN
53
6