Lennox OHR23-105 - Page 20

Page 20
Troubleshooting: Burner fails to start.
Source CorrectionCausesProcedure
Burner Place the trouble light
between the black and white
leads to the burner motor. No
light indicates that no power is
getting to the motor.
Blown fuse Replace the fuse.
Place trouble light between
the black and white leads to
Binding burner blower wheel Turn off power and rotate the
blower wheel by hand. If seized,
the
black
and
white
leads
to
the blower motor. Light
indicates power to the motor
and burner fault
Sized fuel pump
blower
wheel
by
hand.
If
seized,
free the wheel or replace the fuel
pump.
and burner fault.
Defective burner motor Replace the motor.
Troubleshooting: Burner starts, but no flame is established.
Source Procedure Causes Correction
Oil Supply Check tank gauge or use dip stick. No oil in tank Fill tank.
Coat dip stick with litmus paste and
insert into bottom of tank.
Water in oil tank If water depth exceeds 1 inch,
pump or drain water.
Listen for pump whine. Tank shut−off valve closed Open valve.
Oil Filters &
Oil Line
Listen for pump whine. Oil line filter is plugged Replace filter cartridges.
Oil Line
Kinks or restriction in oil line Repair or replace oil line.
Plugged fuel pump strainer Clean strainer or replace
pump.
Open bleed valve or gauge port.
Start the burner No oil or milky oil
Air leak in oil supply line Locate and correct leak.
St
ar
t
th
e
b
urner.
N
o o
il
or m
ilk
y o
il
indicates loss or prime.
Tighten all connections.
Oil Pump Install pressure gauge on pump and
read pressure. Should not be less
than 140 psi.
Pump is partially or completely
frozen. No pressure and the
motor locks out on overload.
Replace pump.
Coupling disengaged or
broken − no pressure
Re−engage or replace
coupling.
Fuel pressure too low Adjust to 100 psi.
Nozzle Disconnect ignition leads. Observe
the oil spray (gun assembly must
Nozzle orifice plugged Replace nozzle with the same
size spray angle and spray
the
oil
spray
(gun
assembly
must
be removed from unit). Inspect the
nozzle for plugged orifice or carbon
Nozzle strainer plugged
size
,
spray
angle
,
and
spray
type.
nozz
l
e
f
or p
l
ugge
d
or
ifi
ce or car
b
on
build−up around orifice.
Poor or off center spray
table continued on next page