If your heating oil tank does not have a gauge on it, you will need to follow the steps below to check for the oil level in your tank.
Step 1: Remove the top fill valve cap.
Step 2: Insert a dry straight stick (one long enough to get to the bottom of the tank) until it reaches the bottom. Mark the stick with a pencil where it meets the top of the fill hole.
Step 3: Once you pull the measuring tool out you can compare the oil level to the top and bottom of your tank. For example, a 275 tank is full at 42 inches.
Step 4: Don't forget to put the top fill cap back on!