Oil boiler service: UK cost, checks and OFTEC engineers

An oil boiler service is a yearly visit from an OFTEC registered technician who strips, cleans and tests the burner, checks the flue, and looks over the oil supply from the tank to the boiler. Oil boilers are common in rural homes off the gas grid, and OFTEC says around one in five UK homes are not on mains gas. If your boiler packs up in January, you can’t just switch to another fuel, so a service that catches faults early is worth more than it is on a gas system.

What an oil boiler service includes

The exact steps depend on the boiler, but a proper service should cover:

The burner. The technician removes it, cleans it and usually fits a new nozzle, which wears and clogs over a year.
Electrodes and ignition. Checked and reset so the burner lights first time.
The combustion chamber and heat exchanger. Cleaned of soot and deposits that cut efficiency.
The oil filter on the supply line, cleaned or replaced.
A flue gas analysis. The technician measures what comes out of the flue and adjusts the burner so it burns cleanly.
The flue and seals, checked for leaks and damage.
Safety devices and controls, including the overheat stat and your thermostat and timer.
The tank and pipework. A visual check for leaks, damage and water in the oil.

At the end you should get a written service record. Keep it with your warranty papers, as you’ll need it for any warranty claim and it helps when you sell.

How the visit works

Plan for the boiler to be off for a couple of hours. The technician needs the boiler cold to work on the burner, so it helps to turn the heating off an hour or so before they arrive. Clear access to the boiler, the flue outside and the tank. If the boiler is in an outhouse or outside casing, make sure the path is clear and any locks are open.

Tell the technician about anything odd you’ve noticed: a smell of oil, smoke from the flue, the boiler locking out or the oil use creeping up. Those clues shorten the hunt for a fault.

Common oil boiler problems

OFTEC suggests some checks before you call anyone out:

Check you have oil. Tank gauges fail. If it’s safe, look in the tank or dip it with a long cane.
Check the power. A blank programmer display can mean a tripped switch at the consumer unit.
Check the programmer and thermostat. A power cut can reset the clock. Turn the thermostat up to see if the heating starts.
Check the pressure on a sealed system. Our boiler pressure guide explains what the gauge should read.
Lockout. You can press the reset, but OFTEC says never more than twice. Repeated lockouts point to a fault that needs a technician.

If oil is leaking, call a technician straight away. Contain it with sand, soil or absorbent material and never wash it into a drain. OFTEC points to the national pollution hotline, 0800 80 70 60, for advice in England, Scotland and Northern Ireland.

Cold radiators with a working boiler are often air in the system. Try our radiator bleeding guide first.

Check the technician is OFTEC registered

Gas Safe registration does not cover oil. For oil, the technician should be OFTEC registered, and you can check on the OFTEC website. OFTEC registered businesses can also self-certify new installations under Building Regulations in England and Wales, which means no separate visit from building control. Many engineers hold both Gas Safe and OFTEC, which is handy if you have an LPG hob or a gas fire as well.

If you’re a landlord

The yearly gas safety check law does not apply to oil. You still have to keep the heating and hot water in safe working order, and an annual OFTEC service with a written record is the simplest way to show you’ve done that. If the property also has gas appliances, they need the yearly gas safety check as well. Book both on the same day if you can.

Repair or replace?

A service often turns up a worn part, and most are cheap to fix. Replacement becomes the question when the boiler is old and the repairs keep coming, when parts are hard to find, or when the heat exchanger or the tank is failing. A new oil boiler costs about £4,500 to £5,500 fitted, and a new tank adds £1,300 to £2,400 if yours needs one.

That’s also the point to price a heat pump. In England and Wales the Boiler Upgrade Scheme pays £7,500 towards an air source or ground source heat pump, plus an extra £1,500 for homes heated by oil or LPG with no mains gas until March 2027. See our heat pump cost guide, the Boiler Upgrade Scheme guide and our heat pump installation page. If you’re weighing up running costs, check the latest kerosene price in our heating oil prices guide.

How to compare quotes

Ask whether the price includes a new nozzle and filter, or whether parts are extra.
Check the tank inspection is included, not sold as an add-on.
Ask for a written service record at the end.
Check travel charges if you live somewhere remote.
Confirm the technician is OFTEC registered for oil boilers, not just for tanks.

When to book

Late summer and early autumn are the best time. Technicians are busiest once the cold arrives, and a fault found in September is far easier to fix than one found on a frosty morning. If you have a gas boiler instead, see our gas boiler servicing page and the boiler service guide.

Typical oil boiler prices

Job	Typical UK price	Notes
Oil boiler service	£100 to £300	Heatable gives labour at £110 to £150 plus £4 to £6 in parts. Older or larger boilers cost more.
Gas boiler service, for comparison	£70 to £150	Which? and Heatable. Oil costs more because the burner needs more work.
New oil boiler, fitted	£4,500 to £5,500	Heatable 2026 figure.
New oil tank	£1,300 to £2,400	Which? figure. Only needed if the tank is failing or in the wrong place.
Boiler Upgrade Scheme grant towards a heat pump	£7,500, plus £1,500 for oil or LPG homes	England and Wales. The extra £1,500 runs until March 2027.

Sources: Heatable (updated 23 February 2026), Which? and GOV.UK, checked October 2026. Prices vary by region; get written quotes.

Oil boiler servicing guides

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Common questions

How much does an oil boiler service cost?

Most UK price guides put it between £100 and £300, with labour usually £110 to £150. Expect the higher end for older boilers, larger systems, remote homes and anywhere the technician has to replace parts such as the nozzle.

How often should an oil boiler be serviced?

At least once a year. OFTEC recommends servicing appliances at least once a year, or as the manufacturer recommends, and says the tank should be inspected as part of that yearly service. Worcester Bosch, for example, can ask for proof of an annual service before it honours its oil boiler heat exchanger guarantees.

Can a Gas Safe engineer service an oil boiler?

Gas Safe registration covers gas work only. For oil, look for an OFTEC registered technician. Many heating engineers hold both, so ask to see both cards if you have gas and oil appliances.

Why does an oil boiler service cost more than gas?

An oil burner needs more stripping down and cleaning. The technician usually replaces the nozzle, checks the oil filter and supply, and inspects the tank, all of which adds time and parts.

Do landlords need to service an oil boiler every year?

The yearly gas safety check law only applies to gas. Landlords still have to keep heating in safe working order, and a yearly OFTEC service is the usual way to show that.

Can I get a grant to replace my oil boiler?

In England and Wales, the Boiler Upgrade Scheme gives £7,500 towards an air source or ground source heat pump. Homes heated by oil or LPG with no mains gas can get an extra £1,500 until March 2027. The grant does not cover a new oil boiler.