Troubleshooting
Guide
25|
Page
6.
MAINTENANCE
Become
familiar
with
the
components
before
attempting
these
procedures,
utilizing
the
Installation
Manual
and
referencing
the
component
schematic
on
the
last
few
pages
of
the
manual.
Safety
is
the
most
important
part
of
this
guide.
These
procedures
must
be
done
by
a
licensed
competent
technician.
A.O.
Smith
is
not
liable
for
the
actions
of
the
technician
if
he/she
fails
to
adhere
to
any
or
all
safety
procedures,
specifically
in
regards
to
electrical
and
gas
safety.
CLEANING
THE
ROD
ASSEMBLY
1)
TOOLS
‐
Gather
the
following
materials
together:
a.
Sheet
of
100
Grit
Sandpaper
b.
#2
Philips
Screw
Driver
c.
Flashlight
2)
POWER
‐
Disconnect
power
to
your
unit
by
either
unplugging
it
from
the
wall
outlet,
or
by
the
circuit
breaker,
depending
on
the
setup.
The
3
‐
digit
LED
on
the
PCB
should
not
be
lit.
3)
FRONT
COVER
‐
Remove
the
front
cover.
It
is
held
on
by
two
screws
on
the
top
corners
of
the
tankless
unit.
4)
ROD
ASSEMBLY
–
a.
Locate
the
black,
yellow,
and
orange
wires
located
in
the
center
of
the
unit.
b.
Remove
the
three
Phillips
head
screws
holding
the
panel
in
place.
c.
Pull
the
assembly
out.
Caution,
all
pieces
are
separate.
Be
careful
to
not
lose
the
sight
glass.
5)
SENSORS
–
It
is
important
to
be
very
gentle
with
the
sensors
while
cleaning
them,
as
they
will
easily
bend
out
of
place.
Their
original
position
relative
to
the
burner
needs
to
be
unaltered
to
function
properly.
a.
Clean
the
flame
sensor
with
100
grit
sandpaper,
thoroughly
to
a
bright
finish.
b.
Clean
the
air
fuel
ratio
rod
with
100
grit
sandpaper,
thoroughly
to
a
bright
finish.
6)
REASSEMBLE
‐
Reassemble
the
unit
in
reverse
order
–
sight
glass,
gasket,
rods,
and
metal
cover.
Key
points
to
remember:
a.
Connect
all
3
wires
on
front
of
burner.
b.
Inspect
all
of
the
gaskets.
Figure
24
