The water heater burner was off on reset. Reset the control and it started then the flame went out. Checked the oil flow, the oil was foamy with air. Checked the oil tank, the level is at approximately 3/4. Checked the oil filter. The filter was dirty but not plugged. Replaced the filter. After replacing the oil filter, checked the flow at the furnace and noticed a lot of air in the line. Bled the line until there was good clean oil at both appliances. Followed the oil line from the tank to the mechanical room, the line sits on top of the concrete, did not see any oil residue or oil spots. The concrete is rough where the oil sits. If there is still an issue with air in the line, recommend replacing the oil line. With the line sitting on the concrete, it can wear a hole a draw in air.