Genie, how does my heating oil tank gauge work?

Dear Diary,

It’s not so much fun making history when it means another historic snow storm. On top of that it’s been just plain cold out there lately. I know people are going to start thinking about how many gallons of heating oil they already used this month and how many they have left in their tank. And that means this Genie’s going to start getting the ole, “How much oil is left in my tank?” questions. I wish it was as simple as just reading gallons on a tank gauge. That’s a start, but a lot of people are confused about what a heating oil storage tank gauge really does.

Here’s the Genie scoop.

First of all, a heating oil storage tank gauge does not measure the quantity of oil remaining in the tank. It’s a float gauge that only measures what percentage of the tank still contains oil. Its job is to tell the oil level in the tank. For example, the tank is ¾ full, ½ full, ¼ full, or nearly empty. But it doesn’t tell the number of gallons of heating oil inside the tank. It’s not built to do that. It’s like the fuel gauge in a car. It doesn’t tell the number of gallons of fuel you have left either, just the percentage of fullness.

Knowing that, another issue specific to heating oil storage tanks in determining how many gallons of oil are in the tank is its shape. That’s a geometry problem. (Maybe I should have paid more attention to that kid Euclid when I had the chance a while back.) Anyway, because most oil tanks are round or oval shaped, a float gauge that measures the height of oil in the tank is only going to be precise at three points:

  1. When the heating oil level is at the top of the tank it’s full. The volume label on your tank will tell its capacity. So can your Aladdin Heating Oil professional.
  2. When the heating oil level is at the bottom of the tank it’s empty. WARNING: Do not run all the oil out of the tank. Any water or sediment in the tank can get drawn into your heating system. That equals a repair bill.
  3. When the heating oil level is exactly in the middle of the tank, no matter what the shape, it’s ½ full. That an easy math problem if you read the tank volume label on the outside.

Like your automobile fuel gauge, this will only help in estimating the number of gallons in the tank.

Here are some other things that might be helpful to keep in mind:

A delivery driver will fill an oil tank until the “tank whistle” sounds, indicating that oil really is at the top of the tank. Of course, the driver will always know exactly how much heating oil he pumped into your tank by looking at his gauge on the truck.

The most common sized residential oil tank holds 275 gallons. But sizes do vary, anywhere from 200 to 275 gallons and there are even some 300 gallon tanks out there. The label that should be welded or glued onto the oil tank will tell you the capacity. Use that to estimate the number of gallons you have in the tank.

To wrap it up, a heating oil tank gauge is always accurate when telling you that a tank is full, half-full and empty. It’s all relative. (That reminds me of the time I landed in Mr. Einstein’s yard by accident. I’d almost forgotten about that.) Anyway, if you really want to know an accurate number of gallons, you’ll need a tape measure and a visit to Calculator Soup. But the easiest answer is — just find out what size your tank is, take a look at the tank gauge to see how full it is, then get out your phone and do the math.

That reminds me, I think I’ll go shovel a path to my fill pipe and give that Aladdin delivery driver a break today.



Aladdin Heating Oil: The fastest, easiest way to order your home heating oil online.

Just click here.