Mollyiom – wrong – Riello burners will not lift oil, most burners fitted with a Danfoss oil pump will however.
That aside, 500l should be plenty to run a boiler, bleed oil line, reconnect and off you go, in theory. But make sure to get a steady stream of oil before reconnecting. Also make sure it is oil and not water as if you have run a steel tank very low you could have dragged some water and muck through.
bear, you are wrong, it may not be recommended but it will lift oil, but im not wanting a who can piss the highest comp here, if you know about oil burners, like ‘know’ you know it will lift the oil.
Know what i mean? 🙂
Oh and wheely good the answer to your question as to why they dont make something to bleed these things, they do, its called a tigerloop