Viessmann VITODENS 242-F Technical Manual page 64

Design information
Cold water installation
B
A
C
For connection locations, see the relevant connection set
5
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
■ The DHW circulation pump connection set (accessories) contains
a DHW circulation pump C and check valve D. The components
are installed in the boiler.
■ The DHW circulation pump C and check valve D from the DHW
circulation pump connection set (accessories) must be installed on
site.
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.
VIESMANN
64
(cont.)
E
S
D
F
G H KLM G
M
K Pressure gauge connection
L Non-return valve
M Drain
N Cold water
O Drinking water filter
P Pressure reducer
R Non-return valve/pipe separator
S Diaphragm expansion vessel, suitable for potable water
Safety valve
The safety valve must be installed.
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 pipe with appropriate thermal insulation in
accordance with the German Energy Saving Ordinance (EnEV). The
Energy Saving Ordinance specifies that the DHW circulation pipe
should 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.
N
G M O P G R N
VITODENS