The P. Gagnon & Son Blog

How to Read Your Heating Oil Tank Gauge

Heating oil tank gauge

Posted: March 9, 2018

Reading your heating oil tank gauge is about the most basic maintenance task you can do for your home heating system – but it’s one of the most important, especially if you’re a will call customer in a cold area southern Maine or New Hampshire (if you receive Automatic Deliveries, you won’t need to look at your gauge very often but it’s still a good idea to know how to do it).

Here are some heating oil gauge basics:

  • Your tank gauge is usually located on top of the tank; look for a clear glass or plastic tube marked with numbers that resemble the gas gauge of your car: F, ¾, ½, ¼. A red marker or float usually indicates how much fuel is left in your tank – if the float is at the bottom of the gauge or not visible at all, your tank is empty or nearly empty.
  • The most common heating oil tank size is 275 gallons, but beware: that size doesn’t indicate how many gallons the tank will actually hold, since some space will always be needed for air and debris in the tank. A typical 275-gallon tank holds approximately 225 gallons of heating oil – which means a tank that reads “½” actually has about 110 gallons left, not 135 or so. Other common tank sizes include 340 and 420 gallons; look for a size indicator on the nameplate or side of your tank.
  • Many factors affect how quickly you’ll burn oil – the size of your home, the outdoor temperature, the efficiency of your equipment, and the air tightness of your home, to name just a few. All these variables make it difficult to estimate how long a tank of oil will last, but if you want a very rough estimate, here’s a starting point: If outdoor temperatures average 32° over a 24-hour period, a typical 2,500 square foot house will burn about seven gallons of heating oil per day. So, for example, if temperatures hover around the freezing mark and you have a quarter of a tank of oil left in your 275-gallon tank (which, remember, holds 225 gallons), you’ll have a little more than 55 gallons left – about enough to last about a week (this is why we say to contact us for a heating delivery when your tank is no lower than one-quarter full).

    Remember: it’s always better to be conservative and order your heating oil early rather than getting stuck in a no-heat emergency. The best way to avoid that risk altogether? Sign up for FREE Automatic Delivery and let us worry about managing your heating oil.

  • To make sure the gauge is working, carefully remove the outer case and gently press the float down. If it bobs back up to the original position, the gauge is working. If the gauge is not working, contact us–we’ll check it out.

Have any other questions about your heating oil tank or heating oil deliveries? Let us know – we’re happy to help. And remember: for reliable heating oil delivery anywhere in our service area, nobody beats P. Gagnon & Son!