beside that alot of larger furance or boiler have dual fuel set up so they can run either natural gaz or fuel oil { diesel fuel } majorty of them used on gaz but keep the oil on stand by or where the gas supply drop a bit.

there are serveral way to get the oil system on but two most common is either high pressure pump or use the steam {more often used with HFO ( Hevey Fuel Oil )]

Merci,Marc

Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)