When your heating oil storage tank runs dry, your oil burner uses up the last of the fuel until the feed line is drained. Consequently, when the tank is refilled, air becomes trapped in the line, forming an air bubble between the oil tank and the burner. This prevents the oil pump from working. All oil burners, such as Carlin, Riello, and Becket are fitted with a bleed screw located on the oil pump. This screw allows you to purge the system of trapped air and get the boiler working again.
Refill your storage tank with heating oil. If you wish to run your boiler before the supply tanker arrives, pour at least 5 gallons of diesel fuel into the tank.
Consult the owner's manual and locate the oil pump air bleed screw on your burner. If you do not have a manual, the oil pump is usually situated on the front of the burner. Look for a single hex head screw protruding from the oil pump body.
Loosen the air bleed screw by turning it counterclockwise with an adjustable wrench and then hand-tighten it back.
Place the wrench over the hex head. Press the oil burner safety reset switch. Once the motor starts turning, undo the bleed screw half a turn. You will hear air hissing out, followed by a stream of oil. As soon as you see a clear stream of oil coming out, tighten the bleed screw and the burner will fire up.
if the burner does not light up, the burner flame-failure mechanism will shut the motor down after 15 seconds. Consequently, you may have to reset the safety switch more than once, depending on how far away the storage tank is located and how much air is in the system.