Lennox O23V Series Installation Instructions Manual page 20

Troubleshooting: Burner fails to start
Source Procedure
Primary Control Place trouble light between
the black and white leads.
No light indicates that no
power is going to the
control.
Place trouble light between
the orange and white leads.
No light indicates faulty
control.
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.
Place trouble light between
the black and white leads to
the blower motor. Light
indicates power to the
motor and burner fault.
Troubleshooting: Burner starts, but no flame is established
Source Procedure
Oil Supply Check tank gauge or use dip stick.
Coat dip stick with litmus paste and
insert into bottom of tank.
Listen for pump whine.
Oil Filters & Oil Listen for pump whine.
Line
Open bleed valve or gauge port.
Start the burner. No oil or milky oil
indicates loss or prime.
Oil Pump Install pressure gauge on pump and
read pressure. Should not be less
than 140 psi.
Nozzle Disconnect ignition leads. Observe
the oil spray (gun assembly must be
removed from unit). Inspect the
nozzle for plugged orifice or carbon
build−up around orifice.
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Causes
Primary or auxiliary control
switch is open
Open circuit between
disconnect switch and limit
control
Low line voltage or power
failure
Defective internal control
circuit
Blown fuse
Binding burner blower
wheel
Sized fuel pump
Defective burner motor
search engine
Correction
Check adjustment. Set the maximum setting.
Jumper terminals; if burner starts, switch is faulty,
replace control.
Trace wiring and repair or replace it.
Call the power company.
Replace the control.
Replace the fuse.
Turn off power and rotate the blower wheel by hand.
If seized, free the wheel or replace the fuel pump.
Replace the motor.
Causes
No oil in tank
Water in oil tank
Tank shut−off valve closed
Oil line filter is plugged
Kinks or restriction in oil line
Plugged fuel pump strainer
Air leak in oil supply line
Pump is partially or completely
frozen. No pressure and the motor
locks out on overload.
Coupling disengaged or broken − no
pressure
Fuel pressure too low
Nozzle orifice plugged
Nozzle strainer plugged
Poor or off center spray
Page 20
Correction
Fill tank.
If water depth exceeds 1 inch, pump
or drain water.
Open valve.
Replace filter cartridges.
Repair or replace oil line.
Clean strainer or replace pump.
Locate and correct leak.
Tighten all connections.
Replace pump.
Re−engage or replace coupling.
Adjust to 100 psi.
Replace nozzle with the same size,
spray angle, and spray type.
table continued on next page