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Updated: May 6, 2024

There are many reasons as to why you should get a new oil tank. A new tank means that it is less likely to leak than an old one. What is more, you might be looking to increase the capacity of your oil tank. 

The installation of a new oil tank needs to meet a number of regulations. 

If you always maintain your oil tank on a regular basis, you wouldn’t need to worry about it for at least 10 years. In fact a well maintained oil tank can last well over 15 years. 

What are the signs of an old oil tank?

During your oil boiler service or inspection by a heating engineer, it is crucial to have your oil tank examined as well. The heating engineer will assess whether a replacement is necessary. It is advisable to periodically inspect your oil tank for any signs of damage. Here are some indicators to watch out for in an oil tank:

  • Oil leaks
  • Sign of corrosion for metal tanks
  • Damages of any type
  • Condensation 
  • Plastic swelling

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Oil tank fitting

While researching oil tanks, you may have encountered the term “bunded” frequently. A bunded oil tank refers to the presence of an additional outer tank surrounding the main storage tank. This secondary tank acts as a protective layer for the primary tank, ensuring containment in case of leaks or spills.

Regulations require oil tanks without bunding to meet specific standards. In Wales, for instance, bunding is mandatory for oil tanks.

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oil boiler
oil boiler

Types of bunding

Integrally bunded

For added protection, your oil tank will be within another layer of tank. These are considered the best type available. 

Double bunded (double skinned)

With this type there are two layers in order to protect you against leaks. This is the most common type used for underground installations. 

Single skin

A single skin oil tank cannot be more than 2,500 litres in capacity and must meet plenty of regulations. Some of these include the following:

  • You tank must be further than 10m from water
  • Not installed above hard ground
  • Away from drains

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Where should I put an oil tank?

There are three places you can use to place your oil tank in. It can be installed outside, inside or underground. 

Outside (above ground)

This is the most common place for most oil tanks. However, there are certain regulations the oil tank must meet before being installed outside. Your tank must be:

  • 1.8 metres from windows, doors, garden sheds and the flue pipe of the oil boiler
  • 760mm from a non-fire-rated boundary
  • 50 metres away from a well, spring or a borehole 
  • 10 metres away from a water source such as a stream, a river or a pond
  • Must not be fitted in an area that might face flooding or near a manhole

What is more, an oil tank needs to be installed on top of a base of concrete or paving slabs. There are certain criteria for the base to meet as well:

The base must cover an area of 300mm around the outside of the tank. 

It must be a fireproof material 

Concrete must be 100mm think and paving slabs 50mm thick (minimum)

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Above-ground indoor

An oil tank can be installed indoors, typically in a garage or outhouse. However, it is essential that the designated space is solely dedicated to housing the oil tank and does not contain any other items.

For internal installation, the tank’s capacity should be below 3,500 liters and accessible from all sides. A minimum distance of 1.8 meters must be maintained between the tank and any doors or windows. It is crucial to consider the indoor environment in the event of a potential leak, ensuring appropriate measures are in place for containment and prevention.


If you’re looking to maximize garden space and conceal your oil tank, underground installation is a viable option. However, it’s important to note that this undertaking can be costly due to its complexity. Furthermore, it requires a significant investment of time and effort.

For underground oil tank installations, a double-bunded tank is necessary to address the potential environmental consequences that may arise from leaks or spills. This additional layer of protection is crucial in preventing soil and groundwater contamination.

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Oil Tank Replacement For Boiler

Which oil tank size is most suitable for my home?

Oil tanks are available in a range of sizes, typically ranging from 500 litres to 10,000 litres. Choosing the best size for your home depends on several factors:

Boiler usage: Consider how frequently you use your boiler and the amount of oil consumed.

Space availability: Assess the space you have for installing the tank and ensure it meets the required dimensions.

In general, a 500-litre oil tank is commonly suitable. However, if you have sufficient space, opting for a larger tank can provide additional storage capacity for convenience and potentially save on delivery costs.

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Oil Tank Replacement Costs?

The cost of a new oil tank can range from £1,100 to £2,000, while installation costs can reach approximately £1,000. It’s important to consider additional expenses as well. The process of draining any remaining oil from your old tank, typically done by your supplier, may cost around £300 to £350. Additionally, if a new trench is required for the oil pipe, an additional cost of approximately £500 may be incurred.

You will be responsible for any oil leaks that might take place. Oil leaks can harm the environment. You might be required to pay to clean the oil spill or any damages.

How do I know when my oil tank needs replacing?

Knowing when to replace your oil tank involves several factors:

Age of the Tank: Typically, oil tanks have a lifespan of around 15-20 years. If your tank is approaching or has exceeded this age, it’s wise to consider replacement even if there are no apparent issues.

Visible Signs of Wear or Damage: Inspect your tank regularly for any signs of rust, corrosion, dents, or leaks. If you notice any of these, it’s a strong indication that the tank may need replacement.

Oil Consumption: If you find that you’re refilling your oil tank more frequently than usual, it could indicate a leak or deterioration in the tank’s integrity. This increased consumption might prompt the need for replacement.

Odors: Any unusual smells around the tank area, particularly the smell of oil, could suggest a leak. Even small leaks can escalate quickly, so it’s important to address any odors promptly.

Environmental Regulations: Keep abreast of local regulations regarding oil tanks. If your tank doesn’t meet current standards or regulations, replacement might be necessary to remain compliant.

Professional Inspection: Schedule regular inspections by a qualified technician. They can assess the condition of your tank and provide guidance on whether replacement is necessary.

Tank Material: Tanks made of materials like steel are more prone to rust and corrosion over time compared to newer materials like fiberglass. If your tank is made of steel and is several years old, it might be more susceptible to issues requiring replacement.

How long is an oil tank good for?

The lifespan of an oil tank typically ranges from 15 to 20 years. However, several factors can influence how long a tank remains in good condition:

Material: The material the tank is made of affects its longevity. Steel tanks are more prone to rust and corrosion over time compared to newer materials like fiberglass, which tend to have longer lifespans.

Quality of Installation: Proper installation by qualified professionals can extend the lifespan of an oil tank. Improper installation, such as inadequate support or poor sealing, can lead to premature deterioration.

Maintenance: Regular maintenance, including inspections for rust, corrosion, and leaks, can help prolong the life of an oil tank. Promptly addressing any issues that arise can prevent them from worsening and potentially extend the tank’s lifespan.

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Do I need planning permissions for an oil tank installation?

You will need planning permissions for an oil tank installation if you live in a listed property. Otherwise, it will depend on where you are going to place your tank and how high it is. To be completely sure, it is better to check with your local council. 

What are oil tanks used for?

Oil tanks are used for storing oil that is used to power your heating system if you have an oil boiler. 

What type of oil tank is the best?

The best oil tank on the market is the integrally bunded oil tank.