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Heating oil explained

What is heating oil?

By Liz Ransome-Croker

Article 1 of 4

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What is heating oil?

We talk you through the basics of heating oil, including the different types of heating oil, what they're used for and the average prices.

Millions of households in the UK are not connected to the national gas grid, and instead rely on heating oil, liquid petroleum gas (LPG), electricity or renewable sources to heat their homes. 

The key difference between energy from the grid and heating oil (as well as LPG) is that heating oil is delivered by road and stored in a tank.

If you're home has an oil boiler, it runs on heating oil. Keep reading to find out what you need to know about heating oil.

You can use our research to discover the most reliable oil boilers, based on ratings from owners and heating engineers.

What heating oil do I need?

There are two types of heating oil are used for domestic heating:

  • Gas oil – also known as 35-second oil or red diesel. This is a heavier oil generally used in older boilers, in agriculture or commercially.
  • Kerosene – also known as 28-second or heating oil. This is a lighter and cleaner fuel and the most common type used in homes in the UK.

If you've just moved into a property, the type of oil you will need is determined by the type of heating system already installed. If your boiler or tank isn't labelled clearly, ask the previous owner what type was used. 

If they can't help, a technician registered with Oftec (the oil-fired industry trade association) should be able to tell you.

If you are able to choose which type of heating oil to use, kerosene is more efficient.

If you are able to choose which type to use, kerosene is the more efficient fuel. In cold weather it is unlikely to ‘wax up’ (form crystals that stop it from flowing as easily) until it reaches around -39°C (although check with the supplier on the type you're getting, as this can vary). 

For more information on how to prevent waxing up, take a look at our tips on maintaining and fixing heating oil problems

Kerosene heating oil

You can buy a premium type of kerosene that contains additives - this makes it burn more cleanly and therefore more efficiently. Premium kerosene usually costs around £20 to £30 more than standard kerosene (based on 500 litres). You can also buy additives yourself, which cost around £15 for a bottle that will treat 1,000 litres of heating oil. 

For certain appliances, such as an Aga, you are required to use additives - you should be able to find this out from the manufacturer.

What does heating oil cost?

The price of heating oil can fluctuate, having risen and fallen throughout the years. For example, the average prices* for a litre of kerosene throughout 2017 were higher than in 2016.

Now, in 2018, the price has risen again. In January 2018 it was 48p - that's a 5p rise compared to January 2017.

Our graphic shows how the prices have changed over time. We will be updating this quarterly.

These price fluctuations can be down to a number of factors, including global production increasing or decreasing, extreme weather or political unrest. But price can also depend greatly on where you live in the UK, the time of year you buy, and the amount you buy.

There are several ways to get a cheaper deal - find out more about how to get the best heating oil prices