Lennox International Inc. o23v - Manual (Page 27)

Page 27
Troubleshooting: Burner fails to start
Source Correction Causes Procedure
Primary Control Place trouble light between
the black and white leads Primary or auxiliary control
switch is open Check adjustment. Set the maximum setting.
the black and white leads.
No light indicates that no
power is going to the switch is open
Jumper terminals; if burner starts, switch is faulty,
replace control.
power is going to the
control.
Open circuit between
disconnect switch and limit
control Trace wiring and repair or replace it.
Low line voltage or power
failure Call the power company.
Place trouble light between
the orange and white leads.
No light indicates faulty
control. Defective internal control
circuit Replace the 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. Blown fuse Replace the fuse.
Place trouble light between
the black and white leads to
the blower motor Light Binding burner blower
wheel Turn off power and rotate the blower wheel by
hand. If seized, free the wheel or replace the fuel
pump
the blower motor. Light
indicates power to the
Seized fuel pump
pump.
indicates power to the
motor 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
Kinks or restriction in oil line
Plugged fuel pump strainer
Replace filter cartridges.
Repair or replace oil line.
Clean strainer or replace pump.
Open bleed valve or gauge port.
Start the burner. No oil or milky oil
indicates loss or prime. Air leak in oil supply line Locate and correct leak.
Tighten all connections.
Oil Pump Install pressure gauge on pump
and read pressure. −70/90 should
not be less than 100 psi. −105/120,
140/154 should not be less than
Pump is partially or completely
frozen. No pressure and the motor
locks out on overload. Replace pump.
−140/154 should not be less than
140 psi.
Coupling disengaged or broken − no
pressure Re−engage or replace coupling.
Fuel pressure too low Adjust 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. Nozzle orifice plugged
Nozzle strainer plugged
Poor or off center spray
Replace nozzle with the same size,
spray angle, and spray type.
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