Viessmann VITOCELL 100-U Installation Instructions Manual page 21

Connecting the domestic hot water side
A DHW
B DHW circulation line
C Visible blow-off line outlet
D Safety valve
E Shut-off valve
F Flow regulating valve
(installation recommended)
G Pressure gauge connection
H Non-return valve
K Drain
L Cold water
Safety valve
The system must be equipped with a
type-tested diaphragm safety valve as
protection against overpressure.
Permiss. operating pressure: 10 bar.
The connection diameter of the safety
valve must be as follows:
R ¾" (DN 20), max. heating load 150
kW.
*1
According to DIN 1988-2, a potable water filter should be installed in systems with metal
pipework. Viessmann also recommends the installation of a drinking water filter when
using plastic pipes according to DIN 1988 to prevent contaminants entering the DHW
system.
(cont.)
M Drinking water filter
N Pressure reducer to DIN 1988-2
issue Dec.1988
O Non-return valve/pipe separator
P The upper indirect coil is provided
for connection to a boiler
R Spring-loaded check valve
S DHW circulation pump
T Diaphragm expansion vessel, sui-
table for drinking water (option)
If the heating load of the Vitocell
exceeds 150 kW, select a sufficiently
large safety valve that is sufficient to
cope with the heating load (see DIN
4753-1, issue 3/88, section 6.3.1).
* 1
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