It’s much better for your heating system if you don’t let the oil tank run out of oil. What happens when your heater runs out of oil is simple: it stops working and you’ll need to order more. There’s a safety primary control in place in every oil heater that shut off the oil burner when there’s no flame.
Sludge, rust and Impurities tend to settle at the bottom of your heating oil tank. When you run out of fuel, these contaminants make their way through the fuel lines and may clog the oil filter, oil pump and oil nozzle. This might result in your oil heater needing needing expensive repairs.
When you refill the tank you need to bleed the air out of the oil line and check for proper operations. Clog nozzles and oil filter's may cause the fire to produce soot or cause a heater fire. A clog oil pump may cause the heater to not run at all. Always have your system check by a trained service technican.
When you refill the tank you may need to bleed the air out of the oil line.