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WL250
Operating,
Installation,
and
Service
Manual
Page
9
‐
Revision:
4
‐
25
‐
2016
HOT
TANK
PRINCIPLES
OF
OPERATION
All
Waterlogic
Hot
Tanks
have
a
built
in
Vent
or
Expansion
Chamber
in
the
top
of
the
tank
except
for
WL270
(GF)
units.
The
Vent
Chamber
allows
for
expansion
of
the
water
when
it
is
heated.
The
chambers
are
separated
by
a
welded
‐
in
tank
baffle.
Water
always
flows
into
the
bottom
of
the
tank
and
out
the
top
to
the
faucet.
The
hot
tank
outlet
tube
has
a
restrictor
in
its
base.
This
ensures
the
reservoir
is
always
full
by
allowing
more
water
in
than
out.
There
is
a
small
hole
in
the
side
of
the
tank
outlet
tube
that
allows
air
and
water
to
pass
into
the
vent
chamber
as
it
is
heated.
Water
in
the
vent
chamber
is
suctioned
back
through
the
outlet
tube
vent
hole
when
water
is
dispensed.
Expansion
of
water
as
it
is
heated
in
the
reservoir
will
push
the
water
out
the
faucet
when
the
outlet
tube
vent
hole
becomes
plugged
with
debris
or
scale.
The
small
Outlet
Vent
Hole
is
susceptible
to
scale
build
up
and
is
a
key
indicator
that
descaling
is
required.
It
is
critical
to
descale
the
Hot
Tank
through
the
vent
line
and
outlet
line
on
a
regular
basis
to
prevent
this
problem.
Descaling
through
the
inlet
and/or
outlet
lines
only
will
not
clean
the
vent
chamber
and
outlet
vent
hole
properly.