How long does an oil tank last?

How long tanks last

OFTEC's home guide puts the expected working life of a fuel tank at around 20 years, and its October 2026 advice gives the same estimate for a new tank that is correctly positioned and installed. That figure is a prompt, not a deadline. A well-sited tank that is checked every year may go on longer, while one that has been knocked, overgrown or sat on a poor base can fail much sooner.

OFTEC's home guide gives one figure for all fuel tanks, plastic or steel. They show their age differently: plastic tanks whiten, crack or change shape, and steel tanks rust, pit or lose their paint. Natural Resources Wales is clear that plastic tanks cannot be repaired, so once one starts to deteriorate the answer is a new tank. Your technician will tell you when replacement is due.

Signs a tank needs replacing

• Plastic tanks: whitening, cracks, splits, bulging or a change of shape.
• Steel tanks: rust, pitting, blistered paint, or oil dampness along seams and welds.
• The base: cracks, sinking or supports that have moved.
• Pipes and fittings: damp patches or stains around valves, filters and pipework.
• The gauge: one that has fallen over or stopped working.
• Around the tank: a strong smell of oil, or plants dying back nearby.
• Your usage: a sudden rise in how much oil you seem to use, which can mean a leak.

UKIFDA, the oil distributors' trade body, says that if a technician flags a tank as at risk, it needs replacing.

Checks you can do yourself

OFTEC recommends an inspection of the tank every year as part of the heating service, plus your own visual checks in between, especially after extreme weather. Natural Resources Wales suggests a monthly walk round:

• cut back plants that hide the tank or its base
• check the base or supports for cracks or subsidence
• look at visible pipework, valves and filters for damage or leaks
• check any bund is free of liquid and rubbish
• make sure the gauge works and any gauge valve is closed

UKIFDA adds a more thorough check at least every six months. Watch deliveries if you can, so the tank is never overfilled.

Why insurers care about condition

OFTEC says most home insurance covers the lost oil and damage to your home after a leak, but not the environmental investigation and clean-up costs, as pollution cover is often capped and sometimes excluded completely. Cover can also depend on the damage coming from a sudden, identifiable event rather than a gradual leak, wear and tear or lack of maintenance. OFTEC says a domestic clean-up bill of more than £20,000 is not unusual, and its October 2026 advice warns costs can reach £50,000. Keep the service reports your technician gives you as proof the tank has been looked after, and read the oil leak section of your policy.

Replacing a tank

Use an OFTEC-registered technician, who can advise on size, siting and whether you need a bunded tank, and who can self-certify the work in England and Wales. In Wales every new tank must be bunded. OFTEC advises against second-hand tanks: their age and condition are hard to verify, moving a tank can stress its walls or base, and selling a used tank voids the maker's warranty. Our guides on oil tank rules and tank sizes cover the choices. A new tank also needs filling, and 1,000 litres comes to around £1,198 at today's typical price, so it is worth planning for when you compare prices for your postcode.