How to Measure Your Oil

Avoid running out of heating oil, costly damage to your boiler and the need for an emergency delivery with our TOP TIPS on how to measure the oil in your tank.

Click here to watch our TOP TIPS Video - How to Measure your Oil

Kettlewell Fuels Day check

Set a regular day to check

However you choose to monitor your heating oil, it is a good idea to set a regular day to check your tank's oil level, for example, each month.

Whether you have a fuel gauge or not, popping a reminder in your phone or marking a specific day on your calendar can make all the difference and gets you into a routine.

Please do remember to check that your gauge is in working order. If it hasn't moved in a month and you know you've been using your heating there's a good chance it's not working, and you may need to get it checked.

Kettlewell Fuels Fuel Oil Tank

Get to know your fuel oil tank

It may sound obvious but it’s helpful to know your starting point. If you’re unsure of the size of your tank and its capacity you should find a label on the tank that tells you. On more recent tanks, it may be on the front or side.

To measure, many tanks have simple float gauges or sight level tubes that allow you to keep an eye on your oil level.

When it indicates that the tank is still about one quarter full, now is a wise time to order. The winter months are the busiest time for fuel oil companies so ordering in plenty of time will avoid leaving it too late.

Kettlewell Fuel Digital Monitor

If you have a digital monitor

If your tank has a digital monitor that plugs into an electric socket inside the house, such as an Apollo or Watchman, ordering when the digit reaches 1 or 2 (1 or 2 bars) is usually the ideal time.

Most systems are designed to flash at either Level 1 or Level 2. When the monitor first starts flashing at these levels, you still have quite a bit of oil left so there’s no need to panic and turn off your heating – the flashing is merely a visible reminder to place your order.

Please note that if fitted correctly the sensors are never placed on the bottom of the tank so even when the monitor first registers zero or zero bars there will still be approximately 10% of fuel left in the tank.

Kettlewell Fuels Dipstick

If you don't have a gauging system or simply want to double check

If your tank has no gauging system, or you want to double-check the accuracy of your gauge, an alternative basic method to monitor how much oil you have left is to dip the tank.

To avoid contamination, make sure you use a designated dipstick that is kept clean and used solely for your oil tank.

To measure your tank manually, take the cap off the top of the tank, which is where the fuel goes in, and put the dipstick right down to the bottom of the tank. When the stick is withdrawn, the oil will leave a mark on the stick consistent with the level of oil. When your tank level gets down to around the last 12 inches (approx. 30cm), we recommend it’s time to order your fuel.

Kettlewell Fuels Oil Level

Don't let your oil level fall below

Apart from averting an oil emergency, keeping approximately 12 inches of oil in the bottom of your tank will also help to prevent disrupting the sediment that settles at the tank's base. This can clog up your supply pipe and lead to costly repairs.

Click here to find out more about How to Look After your Oil Tank

Domestic Heating Oil Graphic

FREE Tank Inspection

Our expert oil tank partner offers a FREE tank inspection.

To arrange an appointment please contact the Kettlewell Fuels team on 01765 640682 or 01765 641139 or

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How to use a digital monitor

Watch our video to find out how to manage and use your digital monitor, which type of digital monitor to choose, where to locate it as well as handy guidance on how to ensure you have sufficient oil in your tank.

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