Symptoms / Consequences	Failure description	Probable cause	Frequency	Remedy	Remedy illustrations
Fuel pump looses prime and burner stops	Pump diaphragm defective diaphragm	Diaphragm (too stiff)	Occasionally	Replace fuel pump diaphragm	22-1, 2, 3
Burner won’t start	Pump frozen motor won’t rotate	Pump gear set lockage or extreme fuel contaminates	Infrequent	Replace fuel pump	21-2, 8, 15, 16, 17, 18, 19
Fuel line leak	Fuel line failure	Loose or stripped fuel line connections)	Infrequent	Tighten fuel line connections	21-15
Fuel flow not visible in transparent filter body burner won’t fire continuously	Main fuel line flow failure	Fuel can vent closed, kinked or no fuel can dip tube, frozen (gelled) fuel (sub-zero), quick disconnect fitting not fully inserted, loose hose clamp	Common	Open can vent, check dip tube, remove filter, snap in quick disconnect, tighten hose clamps	4-1, 2, 3
Burner runs intermittently or stops	Damaged rubber hose	Rough handling	Infrequent	Replace hose	4-3
Burner will not prime or run continuously	Fuel Solenoid body or coil failure	Component failure or loose connection at power cable and coil caused by rough handling or excessive moisture	Occasionally	Check connection or replace fuel solenoid body and coil together	21-2, 19, 20
Fuel sump leak	Fuel sump gasket failure	Broken gasket, poor installation	Infrequent	Replace gasket	21-2, 17, 18
Fuel leak from flow control module	Broken gasket and/or O-ring	Poor installation, component failure	Infrequent	Replace gasket & O-Rings	21-42, 43
Fuel leak from crossover tube	O-Ring failure	Poor installation, component failure	Infrequent	Replace O-Rings	21-2, 17, 18
Burner runs then stops or doesn’t run at all	Corroded control box	Corrosion due to moisture	Infrequent	Dry or replace control box	21-1
Shorted out system or no signal to control box	Broken control box base	Rough handling	Occasionally	Replace control box base	21-1, 21, 22, 26, 27
Burner runs then stops or doesn’t run at all	Broken cad cell causes control sequence failure (burner locks out)	Rough handling	Common	Replace cad cell or re-install components	21-23
Ignition failure	Shorted out electrode due to arcing at the porcelain base of the igniter	Mis-tuned burner (making smoke) or bent electrode tip, or from excessive oil in flame tube	Infrequent	Replace or clean ignition electrode	21-3A, 3B
Ignition failure	Burnt out transformer	Bad power supply (bad line current or defective DC/AC power inverter)	Rare	Replace ignition transformer	21-3A, 3B, 4A, 4B, 5 30,31,32
Ignition failure	Disconnected wire	Loose spade connection	Infrequent	Tighten spade connections	21-30
Burner looses prime and stops	Broken micro-switch causes fuel solenoid to not open	Defective fuel pump diaphragm causes excessive cycling	Rare	Replace float switch and pump diaphram
Motor completely stopped	Electric motor failure	Excessive spilled fuel into motor housing, or burnt motor winding	Rare	Replace motor	21-2, 14, 15, 16, 17, 18, 19, 20, 21, 24, 45, 46, 49, 50,
Symptoms / Consequences	Failure description	Probable cause	Frequency	Remedy	Remedy illustrations
Motor completely stopped	Disconnected power cable	Loose connection	Rare	Check connection	21-23
Motor completely stopped	Collapsed silencer jammed in piston crank	Defective component	Rare	Remove and discard silencer	21-2, 14, 15, 16, 17, 18, 19, 20, 21, 24, 45, 46, 49, 50
Motor completely stopped	Motor temporarily frozen in one position	Burner not used for prolonged period of time	Occasionally	Remove upper fan housing and rotate blower wheel by hand to free motor (power off)	21-33, 34
Poor combustion (dirty flame emitting odor) reduced heat output caused by Low air pressure (< 15 PSI)	Worn piston ring and/or compressor head	Excessive operation in dusty or sandy environment (desert operation)	Infrequent	Replace piston ring and O-Ring and compressor head	21-8, 13, 14, 54, 55, 56, 57
	Air Line leak	Loose connection or stripped threads	Infrequent	Tighten connection	21-13
	Loose air solenoid body connection	Loose connection	Infrequent	Tighten connection	21-10
	Loose compressor filter plug	Loose connection	Infrequent	Tighten connection	21-51
	Atomizing chamber O-ring failure	Broken O-Ring	Infrequent	Replace O-Ring	21-2, 4A, 4B
High air pressure (above 30 PSI) causes poor combustion, & odor	Clogged air filter	Dirty filter	Rare	Replace filter	21-51, 52
No fuel spray or combustion	Failed Air Solenoid body or coil causing lack of fuel atomizing air	Loose power connection at solenoid coil, coil failure, solenoid body failure	Rare	Check power connection or replace air solenoid body and coil	21-8, 9, 10, 11, 12, 53
Bad, uneven, or no fire, low output (produces “fireflys”)	Clogged atomizer bullet (high pressure + 30 PSI)	Contamination in air compressor system	Occasionally	Replace atomizing chamber	21-2, 3A, 3B, 4A, 4B, 5, 6, 7
Air leak causing very little or no fire due to low pressure (under 5 PSI)	Loose atomizer bullet	Cracked housing, failed glue joint	No known failures	Replace atomizing chamber	21-2, 3A, 3B, 4A, 4B, 5, 6, 7
Fuel leaks in lower fan house (fuel & drain connections) or air leak causing low atomizing pressure	Damaged Atomizer O-Rings (located in lower fan housing)	Careless installation	Infrequent	Replace O-Rings	21-2, 4A, 4B
Fuel and air leaks	Broken or cracked die cast components	Physical abuse	Common	Replace broken components	Chapter 21 (ALL)
Unable to assemble burner	Stripped screws	Improper installation	Common	Replace broken components	Chapter 21 (ALL)
Unstable combustion, unable to install burner in appliance	Bent flame tube	Physical abuse	Rare