Oil tank leaking? What to do and when to replace it

If there is a fire, or anyone feels unwell from fumes, get everyone away from the area and call 112 or 999. Keep flames, cigarettes and sparks away from spilt oil.

How can I tell if my oil tank is leaking?

Small leaks are easy to miss. Clare County Council and OFTEC list these signs:

a strong smell of oil near the tank or along the pipe to the house;
damp or oily patches under the tank, or stains on the base or a nearby wall;
a small, irregular drip from the tank, a valve or a joint;
grass or plants dying back near the tank or over the line of the pipe;
oil going faster than usual with no change in how you heat the house;
cracks, splits, bulges or sun bleaching on a plastic tank, or rust patches on a steel tank;
a base that is sinking, cracked or no longer level.

To check the usage, compare your gauge reading with your last delivery docket. If you have kept old receipts, they show how long a fill normally lasts. Our guide on how to check your oil tank level covers the gauge and the dipstick method.

A smell inside the house can also come from a leak outside or at the boiler. See kerosene smell in the house for how to tell oil from fumes.

What to do straight away

If it is safe, stop the flow. Close the valve on the outlet at the tank. If the leak is at the boiler end, switch the boiler off as well. Clare County Council suggests a plastic bucket under a slow drip.
Keep oil out of drains and water. Never use a hose or detergent to wash oil away. Block its path with sand, soil or a spill kit so it cannot reach a gully, drain, stream or well.
Soak up what you can. Sand, soil or absorbent pads work. Bag used material and keep it away from children and pets until a contractor removes it.
Call an OFTEC-registered technician. They can find the source and arrange for the remaining oil to be pumped out and stored while the tank is repaired or replaced. Do not try to move or cut into a tank yourself.
Tell your home insurer early. Clare County Council advises reporting it to your insurer, claims handler or loss adjuster as soon as possible. A specialist oil clean-up contractor may be needed.
If oil may have reached a neighbour's property, tell them.
Work out roughly how much oil was lost. Your delivery dockets and gauge readings help the insurer and the technician.

Who do I report an oil spill to?

If oil has reached, or could reach, a drain, stream, river, lake, the sea or a well, tell your local authority's environment section. Councils deal with most local water pollution reports. The EPA lists these routes:

the National Environmental Complaints Line, 1800 365 123, open around the clock, which passes reports to the right council;
the “See It? Say It!” app, used by every council except Dublin City Council, which has its own online system;
Uisce Éireann on 1800 278 278 if oil may have got into the public water supply or a public sewer.

OFTEC warns that clean-up costs rise quickly once oil reaches groundwater or surface water, so report early rather than waiting to see if it spreads.

Will my insurance pay for an oil leak?

Check your policy wording. Clare County Council notes that many homeowners have the tank and its contents covered by home insurance. OFTEC warns, from a UK perspective, that policies often cover the lost oil and damage to the house but limit or exclude environmental clean-up and damage to neighbouring land, and some only pay for a sudden incident rather than a slow leak. Zurich Ireland points out that escaped oil can leave a home uninhabitable for a time. Ask your insurer exactly what you are covered for before you need it.

When should I replace my oil tank?

OFTEC gives a tank an expected working life of around 20 years and says the risk of a costly failure rises with age. Age alone does not decide it. Get a technician's opinion if you see any of these:

cracks or splits in a plastic tank;
bulging or a change of shape;
sun bleaching of the plastic;
rust on a steel tank;
a gauge that has fallen over or stopped working;
a base that has subsided, cracked or no longer supports the whole tank;
an oil supplier refusing to deliver, or leaving a warning notice on the tank.

OFTEC notes that oil suppliers can refuse to fill a tank they think is unsafe. Zurich Ireland says a tank with defects should be replaced immediately, and that a tank without full horizontal support can warp and crack over time.

Get the tank inspected

OFTEC recommends that the tank is inspected every year as part of the boiler service, with your own visual checks in between and after storms. Zurich Ireland suggests checking it yourself at least twice a year whatever its age. OFTEC also advises having hidden or buried fuel pipework pressure tested at least every five years.

What to think about when replacing it

Use an OFTEC-registered technician to remove the old tank and fit the new one.
Ask whether a bunded tank is needed. Under the building regulations guidance, Technical Guidance Document J, tanks over 2,500 litres, and tanks close to water, drains or wells, should have secondary containment. Our guide to single-skin vs bunded oil tanks explains the rules.
Check the base. TGD J says a tank without a bund should sit on a non-combustible base that extends at least 300 mm beyond each side.
Plan the swap for when the tank is nearly empty, so less oil has to be pumped out and stored.

How much does a new oil tank cost?

We could not find published Irish prices from an official or independent source, so we have not quoted a figure. The cost depends on the size, whether it is bunded, the base, access, and removal of the old tank. Get at least two written quotes from OFTEC-registered technicians and ask each one to list those items separately with VAT.

How to prevent a leak

Book a yearly boiler service and ask for the tank and pipework to be checked.
Look at the tank before and after each delivery.
Keep a record of where underground pipework runs, as Clare County Council suggests, so building or garden work does not damage it.
Do not let the tank run dry. Grit and sludge from the bottom can be drawn into the line.
Think about a leak detection alarm, which Clare County Council suggests along with a bunded tank.

Common questions

How do I know if my oil tank is leaking?

Look for a strong oil smell at the tank or pipe, damp or oily patches under the tank, stains on the base or wall, plants dying back nearby, and oil disappearing faster than your heating explains. Cracks, splits or bulges in a plastic tank and rust on a steel tank are warning signs too.

What should I do first if my oil tank is leaking?

If it is safe, close the valve at the tank to stop the flow. Catch drips in a container and soak up oil with sand, soil or a spill kit. Never hose it into a drain. Then call an OFTEC-registered technician and your home insurer.

Who do I report a heating oil spill to in Ireland?

Your local authority if oil could reach a drain, stream, river, lake or well. The National Environmental Complaints Line, 1800 365 123, passes reports to the right council. If oil may have reached the public water supply or sewer, call Uisce Éireann on 1800 278 278.

How long does an oil tank last?

OFTEC says a tank has an expected working life of around 20 years. Age is only a guide. A tank with cracks, bulges, rust or a sinking base needs attention whatever its age.

Does home insurance cover an oil tank leak?

It depends on the policy. Many policies cover lost oil and damage to the house, but clean-up of contaminated ground and neighbours' land is often limited or excluded. Check your policy and tell your insurer as soon as you find a leak.

Next step

Once the tank is fixed or replaced, find an oil supplier delivering in your area or compare local oil suppliers. If the boiler won't restart after the work, read what to check when your oil boiler is not working.

General guidance for the Republic of Ireland, checked on 10 October 2026. Contact numbers and rules can change, so check with your local authority and insurer.