Riello oil burner

Is your electric air shutter opening? That causes power to come on. Here's a link.
http://www.weil-mclain.com/sites/default/files/field-file/sgo-riello-oil-burner-manual_0.pdf don-ohio (:^)

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!

is the filter clean u might of picked up sludge in bottom tank also blow out the supply lines and re fitt try again

It could be a vacuum hose leaking.

BUrners trip on safety for a number of reasons. When the burner is working you should not see any smoke in the smokepipe. If you do then the settings are off and adjustments need to be made. If the unit does not actually light then the problem can either be with the nozzle, the oil pump or filter. Lastly, you may not be getting spark. If you get more specific I may be able to guide you through step by step.

does it have the air damper installed? You can add a magic heater to the flue and dump heat into your basement.. thats maybe 5 to 10 percent more efficient

www.heatinghelp.com and post question.

i have a riello oil burner 40 F5, starts to fire up for a few seconds and fails , but then it will start for a few minutes...then shuts off... house is not being heated sufficient. There's hot water but after one shower the water starts getting cold....fuel is ok any ideas please

with a forced draught burner the fan motor would be checked via a pressure switch. if the pressure switch is not set correctly or the fan is too weak the contacts will not be made in the switch and the burner will lockout. if the damper is not open enough when the fan runs then the air supply will be too small for the switch to make. check to see if you have a capacitor on the fan windings if this is faulty then the fan will fail intermittently.

Revisit the photocell:
1. Check if you connected the socket end, into the two pins properly, as it is possible to miss a pin.
2. Try to borrow a working photocell or use yours in another burner to make a determination.