The
ball
valve
mounted
on
the
inlet
pipe
must
be
open
in
normal
system
operating
conditions
in
order
to
allow
water
to
be
added
to
the
boiler.
It
may
be
closed
when
it
is
necessary
to
drain
the
system.
The
delivery
and
return
pipes
have
a
diameter
of
¾".
The
correct
functioning
of
the
“
expansion
box
open
”
requires
that
the
expansion
box
is
placed
at
a
height
not
less
than
7
meters
in
respect
to
the
stove.
The
expansion
vessel
must
be
made
of
a
covered
vessel
located
above
the
highest
point
reached
by
the
water
in
the
system.
The
safety,
inlet
and
outlet
pipes
must
be
protected
from
ice
where
this
may
occur.
The
safety
pipe
must
allow
the
highest
part
of
the
generator
to
be
in
contact
with
the
atmosphere
and
not
have
reverse
gradients,
except
for
the
section
intended
to
lead
into
the
upper
part
of
the
expansion
vessel.
The
inlet
pipe
must
allow
the
lowest
part
of
the
generator
to
be
in
contact
with
the
lowest
part
of
the
expansion
vessel
and
must
not
have
reverse
gradients
capable
of
preventing
circulation
by
gravity
in
the
circuit
(safety
and
inlet
pipes,
stove,
expansion
vessel).
The
outlet
pipe
in
contact
with
the
outside
must
have
a
section
at
least
equal
to
that
of
the
safety
pipe.
The
overflow
pipe
may
also
be
used
as
an
outlet
pipe
provided
that
it
has
a
section
not
smaller
than
that
of
the
safety
pipe.
Our
generator
must
not
be
mounted
inside
closed
expansion
vessel
circuits.
2.4
Control
board
wiring
diagram
For
general
purposes,
the
diagram
of
the
control
board
input
and
output
connections
is
given.
This
diagram
is
expressly
intended
for
the
technical
personnel
in
charge
of
installation
and
maintenance.