I A B c
OGB
50
SEDD 690 470 250
OGB
80
SEDD 950 735 245
OGB 100 SEDD 1125 900 255
OGB 120 SEDD 1300 900 430
Connection and installation dimensions of
the
water heater [mm]
CONNECTION TO THE WATER SUPPLY
445
420
(.)
I
350
r
< I I
GJ
r
100
I I
100
I I I
The
water heater connections forthe in-flowing and out-flowing water are colour-coded. The
connection for the supply ofcold water is coloured blue, while the hotwater outletis coloured
red.
The
water heater may be connected to
the
water supply
in
two
ways. The closed-circuit
pressure system enablesseveral points
of
use, while the open-circuitgravity system enables
a single point
of
use only. The mixer taps must also be purchased in accordance with the
selected installation mode.
The
open-circuit gravity system requires
the
installation of a non-return valve
in
order to
prevent the water from draining out
of
the
tank
in the event
of
the water supply running
dry
or being shut down.
This
installation mode requires
the
use
of
an instantaneous mixer tap.
As
the
heating ofwater expands its volume, this causes the tap to drip.
The
dripping cannot
be stopped
by
tightening it further; on
the
contrary,
the
tightening can only damage
the
tap.
The
closed-circuit pressure system requires
the
use of pressure mixer taps. For safety
reasons the supply pipe must be fitted with a return safety valve
or
alternatively, a valve
of
the
safety class that prevents
the
pressure
in
the
tank
from exceeding the nominal pressure
by more than
0.1
MPa. The outletopening on the reliefvalve must be equipped with an outlet
for atmospheric pressure.
The
heating
of
water
in
the
heater causes the pressure
in
the
tank
to increase
to
the level set
by the safetyvalve.
As
the water cannot return to
the
water supply system, this can result
in
the
dripping from the outlet of
the
safetyvalve.
The
drip can be piped
to
thedrain by installing
a catching unit just
below
the safety valve.
The
drain installed below
the
safety valve outlet
must be piped down vertically and located
in
the
environment
that
is free from
the
onset
of
freezing conditions.
In case the existing plumbing does not enable you to pipe
the
dripping water from the return
safety valve into the drain, you can avoid the dripping by installing a 3-litre expansion
tank
on the inlet water pipe
of
the boiler.
In order to provide correct operation of
the
relief valve, periodical inspections of
the
relief
valve must be carried
out
by the user.
To
checkthe valve, you should open the outlet
of
the
return safety valve by turning the handle
or
unscrewing
the
nut
of
the
valve (depending on
the
type of the valve).
The
valve is operating properly if the water comes
out
of the nozzle
when the outlet is open.
18
