Viessmann VITODENS 222-F Technical Manual page 57

Design information
Cold water installation
B
A
C D
For connection locations, see the relevant connection set
A DHW
B DHW circulation pipe
C DHW circulation pump
D Spring-loaded check valve
E Visible discharge pipe outlet point (tundish)
F Safety valve
G Shut-off valve
H Flow regulating valve
(We recommend installation and adjustment of the maximum
water flow rate in accordance with the peak draw-off rate of the
DHW cylinder (see "Specification"))
Note
DHW circulation pump C and check valve D are included in the
DHW circulation pump connection set (accessories) and fitted in the
boiler.
Safety valve
The safety valve must be installed.
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.
VITODENS
(cont.)
F
G H KLM G
E
S
M
N
G M
K Pressure gauge connection
L Non-return valve
M Drain outlet
N Cold water
O Drinking water filter
P Pressure reducer
R Non-return valve/pipe separator
S Diaphragm expansion vessel, suitable for potable water
We recommend installing the safety valve above the top edge of the
cylinder. This protects the 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.
With a line length of 7 m or longer, we recommend the installation
of a DHW circulation line with appropriate thermal insulation in
accordance with the Energy Saving Ordinance [Germany]. This
specifies that the DHW circulation pipe should, in accordance with
the Energy Saving Ordinance, include a circulation pump, a check
valve and a time switch for shutting down DHW circulation during the
night.
Only use the DHW circulation pump connection set, available as an
accessory, for installation in the boiler. The circulation pump is then
controlled by the boiler control unit.
O P G R N
VIESMANN
5
57