Oil boiler rapidly cycling

JoePT

I have an oil fired boiler for my residence, single zone system, as far as i can tell.  The boiler cycles on and off every few minutes, and noticing using a good bit of oil.  I just had it serviced recently...called a guy from an internet site, and not quite sure he's really sure what he's doing.  Mentioned something about the aquastat, but not sure really if it is that or something else?.. Has a new nozzle, and as I mentioned fully serviced for the year just a month ago.  Any thoughts?

World Plumber

nozzle size

Did they use the same size nozzle when they serviced it? Did this start  right after the service? Is the circulator pump running? If it started when It was serviced I would guess that the boiler had been down fired or the pressure increased and the tech put the nozzle listed for that boiler in and not the size that was in it.