Good evening Rob, can you determine the make of the the burner/ if not a photo would help, there are only a few things to go wrong with an oil fired unit and are quite easy to remedy, 
, for instance it could be carbon build up between the ignition electrode ends, which makes them short out on start up, sometimes the carbon falls off of it's own accord and then builds up again, it could be muck in the nozzle especially if the tank got low, it could be condensation or the like on the photo cell, on startup, when you look through the tinted glass, you should see the "spark", do you have a "satronic" control box on the front where you press the "lockout" button?, if so, it's probably a TF802B, it's very easy to remove the front of the control box and with the power to the burner on, use a suitable sized cable to simulate startup of each component, 1st the fan starts, which is also turning the fuel pump, then ignition for about 5 seconds, next the solenoid on the pump opens, the fuel then ignites and the photo cell on seeing a "flame" lets the box know that all is well and the cycle is allowed to progress until the room temp/hot water temp is reached, if your boiler only runs for a short while you need to check the circulating pump it could well be seized after standing idle during the summer, remove the screw in the end of the pump and turn the motor by hand with a screw driver, with the screw still out and room stat calling observe the pump running or stick a small screwdriver in the end and listen for clicking sounds as the pump turns.
Also oil fired units should be serviced TWICE a year.
let me know how you get on, but don't let the service chaps rip you off.
hth,
Rich.
, for instance it could be carbon build up between the ignition electrode ends, which makes them short out on start up, sometimes the carbon falls off of it's own accord and then builds up again, it could be muck in the nozzle especially if the tank got low, it could be condensation or the like on the photo cell, on startup, when you look through the tinted glass, you should see the "spark", do you have a "satronic" control box on the front where you press the "lockout" button?, if so, it's probably a TF802B, it's very easy to remove the front of the control box and with the power to the burner on, use a suitable sized cable to simulate startup of each component, 1st the fan starts, which is also turning the fuel pump, then ignition for about 5 seconds, next the solenoid on the pump opens, the fuel then ignites and the photo cell on seeing a "flame" lets the box know that all is well and the cycle is allowed to progress until the room temp/hot water temp is reached, if your boiler only runs for a short while you need to check the circulating pump it could well be seized after standing idle during the summer, remove the screw in the end of the pump and turn the motor by hand with a screw driver, with the screw still out and room stat calling observe the pump running or stick a small screwdriver in the end and listen for clicking sounds as the pump turns.Also oil fired units should be serviced TWICE a year.
let me know how you get on, but don't let the service chaps rip you off.
hth,
Rich.
