Start at the tank and move in methodically. Check tank strainer and any filters/fire valves etc to the flexi hose. Run a few litres off at the flexi to prove you have decent supply of oil to the burner. If you do then the problem lies on the burner.
The tank at same level as burner on a gravity system is not a problem, even if you have half a tank left.
The tank at same level as burner on a gravity system is not a problem, even if you have half a tank left.
