Filter
Top Products
Table 1
System and General Troubleshooting
PROBLEM
POSSIBLE CAUSE
REMEDY
Thermostat not calling for heat.
Check
thermostat
and
adjust.
Be sure it is
accurate.
If
it is
mercury
type
be sure it
Is
level.
Check
furnace switch
and
main
electrical
Dane!
furnace fuse or circuit
breaker.
No
I)OWer
to
furnace.
Thermostat
faulty.
Remove
thermostat
wires
from
the
oil
primary
control
terminal
T·
T.
Put
a jumper
across T-T.
if
furnace
starts,
reolace
thermostat,
thermostat
sub-base
or
both.
Furnace
will
not start
Oil primary
control
faulty.
Check
reset
button
on
011
primary
control.
Remove
thermostat
wire
from
oil
primary
control
terminal
T1
-12.
Check
for 24
v.
across
T-T.lf
movoltage is
present,
check
for 115v. tooiIDrimarv.1f115v.1s
t 0
Drimarv
control diaanostics.
Cad
cell
wiring
shorted
or
room
light
leaking
into cad cell
compartment.
Check
cad
cell
wiring for short circuits.
Check
for
room
light
leaking
into
cad
cell
compartment
..
Repair
light
leak
if
necessary.
Open
safety switch
Check for
open
high
limit,
auxiliary
limit,
pressure
or
door
Interlock
switch.
No
Fuel
011
Check fuel
oil
supply.
Check
that
all
hand
operated
fuel
oil
valves
are
in
the
open
DOSition.
Fill
oil
storaae
tank
if
necessary.
Clogged
nozzle.
Replace
nozzle
with
high
quality
replacement.
Use
rating
plate
or
Tables
In
Appendix
A
as
a
gUide.
Replace
oil
tank filter or in-line filter
if
used.
Furnace
will
not start
without first pushing oil
primary control reset
button.
(Occurs frequently)
Clogged
oil
filter.
Low
oil
pump
pressure.
Connect
pressure
gauge
to
011
pump.
Adjust
pump
pressure,
or
replace
oil
pump
if
necessary.
Ensure
that
erratic
pressure
readings
are
not
caused
by defective
fuel
oil
line.
Air
getting
into
fuel
oil
lines, or fuel
oil
line
dirty,
clogged, or
in
some
manner
defective.
Check
fuel
011
lines.
Replace
any
compression
fittings
found
with
high
quality
flared
fittings.
Check
for
any
signs of
oil
leaks.
Any
oil
leak
Is
a
potential
source
of air or
contaminants.
Check
burner
motor.
If burner
motor
Is
cutting
out
on
over-load,
determine
why.
Replace
if
necessary.
If
cad
cell is dirty,
clean
it.
(Determine
why
cad cell
Is
getting
dirty).
If
cad
cell
is
poorly
aimed,
realign
it.
NOTE:
The
photocell
should
have
a
resistance
of 100K
ohms
In
absence
of
light,
a
maximum
of
15000hms
in
the
presence
of
light.
Ensure
that
room
light Is
not
leaking
into
the
cad
cell
compartment.
(See
diagnostic
liaht
sectian
\.
Check
fuel
oil
supply.
Check
that
all
hand
operated
fuel
oil
valves
are
in
the
open
POsition.
Fill
oil
storage
tank
if
necessary.
Defective
burner
motor.
Cad
cell
Is
dirty or defective
No
fuel
oil.
Furnace starts,
but
shuts
off requiring
manually resetting
the
Clogged
nozzle.
Replace
nozzle
with
high
quality
replacement.
Use
rating
plate
or
Tables
In
ArlOendix
A
as
a
lJuide.
Reolace
oil
tank filter or in-line filter
if
used.
primary control reset
button.
Clogged
011
filter.
Low
oil
pump
pressure.
Connect
pressure
gauge
to
oil
pump.
Adjust
pump
pressure,
or
replace
011
pump
if
necessary.
Ensure
that
erratic pressure
readings
are
not
caused
by
defective fuel
oil
line.
Check
fuel
oil
lines.
Replace
any
compression
fittings
found
with
high
quality
flared
fittings.
Check
for
any
signs of
oil
leaks.
Any
oi/leak
Is
a
potential
source of air or
contaminants.
Check
burner
motor.
If
burner
motor
is cutting
out
on
over-load,
determine
why.
Reolace
If
necessary.
Drain
fuel
oil
storaae
tank
and
reoIace
fuel
011.
(Consult with
fuel
oil
suPDIier).
Air getting
Into
fuel
011
lines,
or fuel
011
line
dirty,
clogged,
or
in
some
manner
defective.
Defective
burner
motor.
Water or
contaminants
in
oil.
Frozen
oilUne.
GentJy
warm
oil
line.
Insulate
011
line.
(Outdoor
piping
size
may
reqUire
increased
diameter).
20