Oil Burner Problems:

Please read this warning. If you are not sure about your ability to work on an oil burner, please stop, and call a professional. there is a real danger of fire explosion soot damage severe burns and death. 

If you have an older oil burner, it will be possible to push the red reset button on the cad cell relay, or the control, over and over again, Your oil company has probably put a note saying "
push only once". Newer oil burners will lock you out if you push the button more then 3 times, preventing you from creating a dangerous situation. It you are looking for instructions on how to get your newer burner out of lock out mode. The oil burner shuts off for a reason, and pushing the button over and over again does not correct the problem, in fact it can cause much bigger ones. For example, if your transformer is failing intermittently, and you push the reset button, oil is pumped in to your combustion chamber, and is not ignited, if you push the button over and over again you can fill the combustion with allot of oil, then the transformer decides to work, now you have an explosion.
The same thing can happen with a partially clogged nozzle or poor oil flow because of clogged filters or strainers. The bottom line is DO NOT PUSH THE RED BUTTON MORE THEN ONCE!!. If it does not start you have a problem that needs to be fixed before your oil burner will run correctly.
I ran out of oil, I just had oil delivered, but my boiler will not run.!
I have pushed the reset button and nothing happens.! A lot of things happen when an oil burner runs out of oil, 1 you suck all the sludge from the bottom of your oil tank in to your oil lines filters strainer and nozzle, 2 you lose your prime (in most situations) 3 your filter can become clogged 4 your oil lines can become clogged 5 your strainer can become clogged and your nozzle can become clogged, So just because you got a full tank of oil, this does not mean you are all set, you should replace your filter, your nozzle and your strainer, and you may need to have your oil lines blown out. If you let your system run out of oil, Call your plumber.
Thanks to masterplumber.net for this info