Leaking Oil Tank: What To Do

The short answer

If your oil tank is leaking, stop the leak if you can, contain the oil with sand or absorbent material and keep it out of drains. Report any oil that reaches water to the Environment Agency on 0800 80 70 60, tell your insurer, and have a specialist transfer the oil and replace the tank.

Signs of an oil tank leak

Not every leak is obvious. Look out for:

• A strong smell of kerosene or heating oil around the tank or in the house
• Dark, oily stains on the base, ground or nearby walls
• Dead or discoloured grass and plants near the tank or pipe run
• An oily sheen on puddles, ponds or ditches
• Using oil faster than normal, or the gauge dropping when the heating is off
• Oil inside the bund of a bunded tank, which means the inner tank is leaking
• Cracks, splits, bulges or white stress marks on a plastic tank, or rust and weeping seams on a steel tank

What causes oil tanks to leak?

Age

Most domestic tanks have a working life of around 20 years. Plastic becomes brittle with UV exposure and temperature changes, and steel rusts, especially from the inside where water collects. See our guide to water in oil tanks.

A poor base

A base that is uneven, cracked, sinking or too small puts stress on the tank and can cause it to split.

Failed fittings and pipework

Many leaks come from the outlet valve, filter, or the pipe to the boiler rather than the tank itself. Underground pipe runs can leak for a long time before anyone notices.

Accidental damage

Impact from vehicles or garden machinery, falling branches and attempted oil theft can all damage a tank.

Will my insurance cover an oil leak?

Many home buildings policies include cover for accidental oil leaks, including clean-up of your property. Clean-up costs can be high, especially if oil reaches the soil under the house or a neighbour’s land. Cover varies, and insurers may limit or refuse claims where the tank wasn’t maintained or didn’t meet regulations, so check your policy and call your insurer before work starts. Keeping records of annual tank inspections helps.

Repair or replace a leaking oil tank?

A leaking valve, filter or pipe can usually be repaired or replaced on its own. A crack, split or corrosion in the tank itself almost always means the tank should be replaced. Patches aren’t a reliable long-term fix, and an old tank that has failed once is likely to fail again.

When we replace a leaking tank, the remaining oil is pumped into clean holding tanks and filtered back into the new tank. The old tank and any contaminated waste are removed and disposed of responsibly, and the new tank is assessed against current regulations, so it may need to be bunded or moved. Read about our oil tank replacement service and what a replacement costs, and whether you need a bunded tank.

How to prevent oil tank leaks

• Have the tank and pipework inspected every year with your boiler service
• Check the tank, base and bund yourself every few months
• Replace an ageing tank before it fails rather than after
• Keep vegetation and stored items away from the tank
• Fit a remote oil level gauge so unusual oil loss is spotted quickly
• Choose a bunded tank, which contains a leak from the inner tank

Frequently asked questions