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    Heating Oil Tank Sizes

    Heating Oil Tank Sizes

    If you’re installing a new oil storage tank, whether it’s a replacement for an old one or for a new build, chances are the conversation will have turned to what size oil tank you need. Oil storage tanks come in all shapes and sizes these days, and can be plastic or metal, single-skinned or double-skinned, designed for residential or commercial buildings. So, deciding which type and size of oil tank you need can be a bit of a conundrum. Let’s put some clarity onto the situation.

    About your oil tank

    There are different oil storage tanks to suit different requirements but the first thing to mention is that you need to make sure it has been manufactured in accordance with OFTEC’s standards – OFS T100 for plastic tanks and OFS T200 for steel tanks.

    You may also find that it is mandatory to have a bunded (double-skinned) tank if it is going to be sited near any controlled water system, such as a river or a well. Generally, oil tanks last for about 20 years, as long as they are serviced annually by an OFTEC registered engineer. They will be able to advise you if you need to replace your oil tank, or your oil supplier will notify you if there are any issues with your tank, such as a leaking valve, and may refuse to deliver out of safety concerns if the problem is serious.

    Oil tank sizes for residential properties

    The size of your oil tank determines how long your heating oil will last and how often it needs to be filled up, which has an impact on your monthly budgeting. Domestic oil tank capacity starts from around 500 litres, rising to 10,000 litres, and which one you choose depends on your circumstances.

    Sometimes you may be restricted on the size you can opt for because of where your oil tank is sited. So, if you want a bigger tank, you may have to move it to a different location, if you can. The advantage to a bigger tank is being able to refill with a bigger volume of oil, which should last longer.

    Before you settle on the size of tank you need, consider the following points.

    1. The size of the property – it’s not the square footage, it’s how many rooms in the house need to be heated. A good rule of thumb is to allow a minimum of about 500 litres per bedroom, then add 500 litres for the living room and any other room you spend time in. You will also find that most oil fuel suppliers have a minimum capacity of 500 litres. So, if you live in a one-bedroom house, you will need a tank capacity of 500 litres and if you live in a four bedroom house, you will need a minimum of a 2,000 litre tank.
    2. The number of people living in the property – this is usually linked to the number of bedrooms so the rule of thumb still applies, but remember, if you’re a couple you will be sharing a bedroom. So, if you have one bedroom but there are two of you in the property, you will need an oil tank bigger than 500 litres. If there are children sharing a room, again, opt for a bigger tank (if you have the room).
    3. How much oil you use – this might not be easy to work out until you have been living in the property for a year – we say a year because the amount you use in the summer will be very different to what you use over the winter. However, the previous owners will be able to guide you.
    4. How much space there is for your oil tank – at a lot of properties, the amount of space you have may well dictate the size of tank you settle on. Most oil tanks at domestic properties are located outside, which is often the safer option, but they can be installed underground, in a building or a basement. When you’ve decided where you want to put your oil tank, you need to make sure of the following (even if you’re replacing an old oil tank):
    5. It is not near any fire or heat source
    6. It is 1.8m away from non-fire rated building eaves or buildings, like a garden shed or outhouse
    7. It is 1.8m away from any openings, like windows and doors, in a fire rated building, such as a garage and your house (brick based)
    8. It is at least 600mm away from any trees, hedges or other foliage
    9. It is at least 760mm away from any boundaries, like a wooden fence, that is not fire rated
    10. There is sufficient access for your oil suppliers to make a delivery
    11. Your OFTEC registered engineer has easy access to the oil tank for maintenance and servicing
    12. It is sheltered from the wind, rain, sun and other weather extremes
    13. It must sit on a base that is sturdy and is able to take the weight of a full tank of oil, such as concrete.


    Most domestic properties in the UK have oil tanks that are between 1,000 litres and 2,500 litre capacities. One other point to mention, don’t go for a bigger sized tank just because you can. If you are only using 500-1,000 litres of oil a month, there’s no point having a 2,500 litre tank installed. Not only will the servicing be more expensive, you may find that the oil in the tank settles quicker than you can use it and therefore, any dirt or silt that’s collected may end up being pulled into your heating system and cause an even greater problem.

    BoilerJuice is the UK’s first heating oil comparison price platform with the aim of helping you find the best heating oil price in your area, quickly and easily. We work independently from heating oil companies and ensure our service is always totally impartial and provides consistently competitive prices, saving you money and time.

    Make sure you never run out of oil by signing up for a BoilerJuice Connected account. You will get a BoilerJuice Monitor complete with installation instructions and we are more than happy to get one of our professional engineers to install it for you for a totally hassle-free installation. The monitor registers your oil levels, how much oil you use over a month or quarter, forecast your upcoming oil consumption and automatically place an oil order. You will receive an email confirming your order and be confident that we have taken advantage of the best oil prices on your behalf.

    Get your personalised home heating oil quote in just 30 seconds and sign up for your BoilerJuice Connected account today.

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