Which? uses cookies to improve our sites and by continuing you agree to our cookies policy.

Heating oil explained

Heating oil tanks

Article 3 of 5

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

Heating oil tanks

Read our guide to heating oil tanks to understand about the different types, prices and sizes, as well as regulations you'll need to adhere to.

Heating oil tanks are made from fabricated steel or plastic and can be installed inside, outside or underground. Either type can be single-skinned, double-skinned (where the tank has two layers) or integrally bunded (bund means protective layer).

Integrally bunded tanks consist of one tank sitting within another, the outside one housing the main tank's fittings and vents. These tanks offer better protection than double-skinned tanks as there is more room between the two layers to prevent oil leaking externally.

Read on to find out all you need to know about heating oil tanks, including the types, essential measures to safeguard against leaks, and maintenance. 

If you're thinking of updating your heating system, it's worth taking a look at our boiler reviews, which include oiler boilers - just use the left-hand menu to select the type you want.

Heating oil tanks: what you need to know

Most single and double-skinned tanks need to have a bund built around them for protection, although this will depend on where you live and the position of your tank. The bund can hold 110% of the tank's contents. Take a look at our page on maintaining and fixing tank problems for more information on preventing and dealing with leaks.

If you're thinking of getting a home heating oil system or changing your current tank, it's important that you get one that is manufactured to Oftec (the oil-firing industry trade association) standards. An Oftec-registered technician can help you choose the type of tank and where it can or should sit so that it complies with regulations, which vary across the UK. 

There are regulations determining how and where tanks should be installed to limit environmental and fire risks, as well as ensuring it complies with building regulations - which also vary across the UK. An Oftec-registered technician will be able to tell you what is and isn’t feasible, or whether your current tank meets regulations. You can visit the Oftec website to find one in your area, or contact the Environment Agency for further advice.

It is important also that your tank is inspected annually by an Oftec-registered technician, which costs around £70 and £100, to ensure it is in good working order. If you have moved into a new property and ‘inherited’ your heating oil tank, it's worth arranging an inspection.

Steel tanks have an oil-resistant coating, which needs to be maintained to prolong the life of the tank. Check with the manufacturer to find out what maintenance is needed besides yearly servicing.

Heating oil tank sizes and prices

Tanks can vary in size from around 1,000 to more than 3,500 litres (although these tend to be used commercially) and prices range from around £500 for a small single-skinned tank to more than £2,000 for a large integrally bunded one. Some manufacturers offer a bespoke service to create a tank to suit the consumer's needs. 

All heating oil tanks should have a gauge in one form or another to indicate how much oil is left in the tank. This may be on the tank, next to the tank, or displayed remotely. If your tank doesn't have one, you can buy one costing anything between £25 for a basic gauge, to more than £80 for a digital remote one. 

It's important to keep a close eye on your oil tank gauge so your supply doesn't get too low. Make sure you order before it becomes less than a quarter full, especially in winter. 

Don't pay more than you have to for heating oil. Read our expert advice on how to get the best price for heating oil.