Troubleshooting
Guide
35|
Page
DESCALING
THE
UNIT
Hard
water
is
a
severe
problem
for
the
copper
coils
inside
heat
exchangers.
Heat
exchanger
failure
due
to
scale
buildup
from
hard
water
conditions
is
NOT
covered
by
warranty.
It
is
highly
suggested
that
a
scale
inhibitor
be
installed
before
the
cold
water
inlet
after
this
procedure
is
done.
1)
TOOLS
‐
Gather
the
following
materials
together:
a.
Pump:
The
pump
should
provide
a
minimum
of
1GPM
through
the
heater
b.
Cleaning
Solution:
Food
grade
citric
acid,
food
grade
phosphorus
acid
c.
Water
hoses
d.
Bucket
2)
SETUP
‐
Disconnect
power
to
the
unit
3)
WATERLINES
–
Assumes
isolation
valves
with
drain
ports
are
installed
a.
Isolate
the
unit
by
closing
the
incoming/outgoing
water
isolation
valves
C
and
D.
b.
Connect
hoses/pump
to
the
drain
ports
of
the
isolation
valves:
Outlet
of
the
pump
to
valve
B,
and
another
hose
from
Valve
A
to
the
bucket.
4)
PUMP
–
a.
Fill
the
bucket
with
5
gallons
of
diluted
solution.
Dilution
ratio
depends
on
the
cleaning
solution
used.
b.
Place
the
pump
into
the
bucket
if
it
is
submersible,
or
use
an
inlet
hose
into
the
bucket
if
it
is
not
submersible.
5)
DESCALE
a.
Open
valves
A
and
B.
b.
Circulate
descaling
solution
through
the
unit
for
45
minutes.
6)
CLEANSE
THE
SYSTEM
–
Flush
the
chemicals
out
of
the
heat
exchanger
with
fresh
water.
a.
Close
valve
A
and
B.
b.
Open
valve
D
and
run
fresh
water
through
the
PRV
for
15
minutes.
c.
Clean
the
filter
after
flushing
the
unit
with
fresh
water.
d.
Once
the
unit
is
flushed
and
cleansed,
close
A
and
B,
open
C
and
D,
and
reconnect
power
to
the
unit.
321922
‐
000
Figure
41
