Riello 721t - Home

The Riello 40 Series F3 Burner has a firing range from .50 Gallons per hour to .95 gallons per hour. The burner is adjusted by the tech for the proper BTU input.

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 (:^)

You need to measure the manifold pressures before and after the gas valve and adjust accordingly to fuel used, 3.5" NG or 11" Propane.

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

This is due to a "Lock-Out" Check your flame sensor for carbon build up. Possible heat exchanger blockage.
The reason he used a flashlight was to trick the burner into seeing a flame, not a good idea for a novice.

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.

Unfortunately, Riello does not release manuals other than to heating professionals.

Good Luck!

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.