I have a riello burner 40 it will fire and come to temp but wont refire, goes into lockout
My first guess would be that it sounds like a clogged oil filter, air in your fuel line, is piping overhead, or leak in a fitting or connection causing it to loose it's prime when running.
I have also seen primary controls that are faulty do this, watching the complete cycle of the run time will give you more clues as to when the control actually locks out. Does it lock out during the run cycle as the boiler reaches temp.? If so,check for oil line and suction issues as stated above.
If it locks out on start up after reaching boiler set temperature, if hitting reset right away burner doesn't start and lock out occurs with no motor engaging, check motor (Note: Some motors when HOT will not kick in when powered, but after they cool down naturally they start, motor shaft may also be bound up tight, replacement is necessary) if burner motor spins but does not fire, check for fuel flow to the nozzle, be sure oil is pumping to the nozzle, if it is, clean cad cell eye, and check transformer for spark, if all is good.. replace primary control.
Disclaimer:
Of course all this information is technical troubleshooting information and should be performed by a Licensed Technician, not knowing how to properly test for flame failure can cause injury, fire or worse! Consult a technician in your area if you are not proficient at oil burner repair!
