When Should I Order More Heating Oil?

You know what’s less fun than running out of heating oil in the middle of the night in the middle of winter? Running out of heating oil in the middle of the night in the middle of winter when your significant other reminded you to order some a couple of days ago.

Yeah. Not good.

But hey, it doesn’t have to be so hard to keep your tank full—and it starts with knowing exactly when to order.

Understanding Heating Oil Tank Sizes

In order to know when to order oil, first you need to know how much oil you have. And to know how much oil you have, you need to know how big your oil tank is. While there are a variety of oil tank sizes ranging from 120 to 330 gallons, most heating oil tanks have a total volume of 275 gallons and can safely hold 240 gallons of heating oil.

Not sure what size you have?  Grab a tape measure and physically measure the dimensions of the tank. You’ll need to know the height, width, and length of the tank and then you can click here to compare those dimensions with home heating oil tanks sizes.  So, if your tank measures 44” in height,  27” in width and 60” in length then you have a 275 gallon tank.

After you know your tank size, next you’ll need to figure out how much heating oil you currently have in your tank. In order to do this, check the oil tank gauge - most likely located on the top of your tank.

If your gauge signals it’s half full, you probably have about 120 gallons in your oil tank. (Remember - a typical 275-gallon residential oil tank safely holds 240 gallons of heating oil). If you don’t have a gauge or it’s broken (eek!), we recommend you spend a few dollars and call your local HVAC company to get a gauge installed. Believe us when we say, it’s worth the expense to ensure that you don’t run out of oil. The last thing you need is another person to tell you, ‘I told you so.’

Understanding How Much Heating Oil is in Your Tank

Based on your oil tank gauge reading, our handy little grid below will give you an idea of the approximate number of gallons of heating oil you have left in your oil tank – and how many gallons you’ll need to fill it back up.

Oil Level Gallons you have Gallons you need to fill your tank 
Empty (Doh!) 00 240
1/8 30 210
1/4 60 180
3/8 90 150
1/2 120 120
5/8 150 90
3/4 180 60
7/8 210 30
Full 240 00

*NOTE: Figures above are approximate and based on a 275-gallon tank. 

How Long Will the Heating Oil in My Tank Last?

Now that you know how much oil is in your tank, you’re almost ready to find out when you should order more heating oil. Before we can do that, though, you’ll need to know how long that heating oil is likely to last, because that will affect when to order more. 

As a general rule of thumb, for a 2000 square foot home a ¼ tank of heating oil will last approximately one week during the winter.  HOWEVER, there are a lot of factors that can affect your usage such as:

  • The temperature outside. Colder outside temps increase the rate of heating oil consumption. Winter = more fuel use = faster consumption, summer = less fuel use = slower consumption.

  • How warm you keep your house. Setting higher temperatures increases the rate at which heating oil will be consumed. Keeping your home cooler will slow consumption—but it might also make your family members hate you. #thermostatwars

  • What else you’re heating? Are you also using heating oil to heat your hot water? Some homes rely on the furnace to continuously heat hot water, while others use tankless or electric systems, which reduce oil consumption.

  • The weather outside. Believe it or not, wind can significantly increase the rate of heat loss from a home. Your home’s insulation (or lack thereof) and draftiness will make a difference in how fast you consume oil.

  • Your oil burner’s efficiency? The efficiency of your heating equipment can vary widely by design, from say 65% efficient for an old, antiquated, not-well-maintained oil burner, to better than 90% efficiency for a properly tuned, newer, high efficiency heating system. Cleaning and maintaining your heating system annually makes a huge difference in how quickly oil is used.

“Order at a quarter”

But who needs all these numbers anyway? There’s a much easier way to never run out of oil—and all you have to do is remember to “order at a quarter.” We recommend this strategy mostly because it rhymes and it’s fun to say, but also because it helps prevent running out of oil. And nobody wants to run out of oil.

Not only does it typically result in lots of arguing about who forgot to place the order – but it’s also bad for your oil tank. When older systems get below 1/8 of a tank, it can cause sediment from the bottom of the tank to get into the fuel lines and gunk everything up.

Plus, it’s always a good idea to place an order before you’re right about to run out. It’s like bread and milk at the grocery store—as soon as a storm rolls in people run to the store and buy bread like it’s going out of style. Same thing happens with heating oil – when it gets cold, everyone orders, and with a first come first served system, you want to make sure your order is in the queue before the mad rush.

Have more questions? We have answers. Be sure to check out our Heatable FAQs for more very punny answers to all your burning (ha – see what we did there?) heating oil questions.

Stay cozy out there!

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