How much does an oil boiler cost in the UK?
An oil boiler installation costs £3,500 on average in the UK. Most jobs fall between £2,600 and £6,000 supplied and fitted. Type of job: Like-for-like boiler swap £2,600 to £3,600; Oil combi or system change £3,600 to £4,800; New boiler plus new tank or relocation £4,800 to £6,000. Prices reviewed July 2026.
An oil boiler is priced supplied and fitted. A like-for-like swap is cheapest, while an oil combi conversion or a new install with a fresh oil tank costs more, so most jobs land between £2,600 and £6,000.
Oil boiler cost calculator
Use the calculator to price your oil boiler installation in 2026. Adjust the options and area for a UK cost range. Nothing is sent anywhere.
Oil boiler cost breakdown
Typical oil boiler installation costs, by option:
| Type of job | Typical UK cost |
|---|---|
| Like-for-like boiler swap | £2,600 to £3,600 |
| Oil combi or system change | £3,600 to £4,800 |
| New boiler plus new tank or relocation | £4,800 to £6,000 |
What's included in the price?
Typical oil boiler installation prices include:
- The oil-fired boiler and standard flue
- Removal and safe disposal of the old boiler
- Installation, commissioning and burner setup by an OFTEC engineer
- A system flush and a magnetic filter
- A carbon monoxide alarm, required with a new appliance under Approved Document J
- OFTEC and building control notification, plus warranty registration
What changes the price?
The things that move oil boiler installation prices most:
Like-for-like swap versus converting to an oil combi
An internal floor-standing boiler versus an external cased unit
Brand, output and warranty length
Whether a new oil storage tank is fitted at the same time
Moving the boiler, and any new flue or pipework runs
These are why two quotes for the same job can differ, and the only way to know your price is to get prices from local firms (through Bark; we may earn a fee, at no extra cost to you).
How the price is built up
The bulk of the price is the boiler itself plus the OFTEC engineer's time, and a like-for-like swap in the same spot is the cheapest route because the existing flue, oil line and pipework usually stay put, which is why these jobs land near the £2,600 floor. Costs build from there: an external cased boiler or a conversion to an oil combi means more pipework and a pricier unit, while a new bunded oil tank, a new flue route or moving the boiler each add materials and labour. A longer warranty, a magnetic filter and a full system flush push a fuller job towards £6,000. On a typical £3,500 job the boiler and parts account for roughly £1,700 to £2,400, with the rest going on one to two days of OFTEC labour, so the split is fairly even and tilts towards materials on external and combi models.
Ways to keep the cost down
- Keep the boiler in its existing position and reuse the oil line and flue where you can, since relocation and a new tank are the biggest add-ons.
- Get three fixed quotes from local OFTEC registered engineers rather than a national firm, as supply-and-fit prices for the same boiler vary widely in rural areas.
- A like-for-like swap is the cheapest job, so only convert to an oil combi if your hot water demand genuinely needs it.
- If your oil tank is genuinely due, replace it in the same visit to save a second callout, but do not renew a sound tank just because the boiler is being changed.
Does where you live change the cost?
In London, an oil boiler installation typically costs around £4,200 supplied and fitted, about 20% above the UK average of £3,500. In the North, Scotland and Wales the guide figure is nearer £3,400.
| Region | From | Typical | Up to |
|---|---|---|---|
| Midlands / East (UK average) | £2,600 | £3,500 | £6,000 |
| London | £3,100 | £4,200 | £7,200 |
| South East / South West | £2,700 | £3,700 | £6,300 |
| North / Scotland / Wales | £2,500 | £3,400 | £5,800 |
Guide prices supplied and fitted, scaled with the same regional multipliers as the calculator. Not quotes.
Oil boiler cost in major UK cities
| City | From | Typical | Up to |
|---|---|---|---|
| Belfast | £2,500 | £3,300 | £5,700 |
| Birmingham | £2,600 | £3,500 | £6,000 |
| Bristol | £2,700 | £3,700 | £6,300 |
| Cardiff | £2,500 | £3,400 | £5,800 |
| Edinburgh | £2,500 | £3,400 | £5,800 |
| Glasgow | £2,500 | £3,400 | £5,800 |
| Leeds | £2,500 | £3,400 | £5,800 |
| Liverpool | £2,500 | £3,400 | £5,800 |
| London | £3,100 | £4,200 | £7,200 |
| Manchester | £2,500 | £3,400 | £5,800 |
| Newcastle | £2,500 | £3,400 | £5,800 |
| Sheffield | £2,500 | £3,400 | £5,800 |
City guide estimates, scaled by local labour costs. Indicative averages for oil boiler installation, not quotes.
Oil heating is a rural, off-grid job, so callout and labour can cost more where OFTEC engineers are thin on the ground, such as parts of Scotland, Wales and the South West. The boiler itself costs about the same everywhere.
Compare this with a real quote
The figures above are guide prices. Two or three quotes for your oil boiler installation tell you what it costs where you live.
Free and no obligation. You answer a few questions on Bark, local pros get in touch, and you decide who, if anyone, to hire. We may earn a fee, at no extra cost to you.Common questions
How much does it cost to replace an oil boiler?
A like-for-like oil boiler replacement typically costs £2,600 to £3,800 supplied and fitted with a mid-range brand such as Grant, Warmflow or Worcester Bosch. Converting to an oil combi, moving the boiler, or fitting a new oil tank at the same time pushes the total towards £4,800 to £6,000. Oil boilers cost a little more than the gas equivalent because the units are pricier and the work needs an OFTEC registered engineer.
What changes the price of an oil boiler installation?
The biggest driver is how much changes beyond the boiler itself. A straight swap that reuses the existing oil line, flue and pipework is the cheapest job. Fitting an external cased boiler, converting to an oil combi, running a new flue, or replacing the oil storage tank all add materials and labour. Brand, output and warranty length move the unit price, and rural callout charges can add more where engineers are harder to find.
Is an oil boiler cheaper than a heat pump?
To install, yes. A new oil boiler runs £2,600 to £6,000 fitted, while an air source heat pump is usually £8,000 to £14,000 before the Boiler Upgrade Scheme grant brings it down. If you are heated by oil or LPG with no mains gas connection, which describes most people reading this page, the grant is £9,000 rather than £7,500: gov.uk pays an extra £1,500 on top of the standard amount until March 2027. That is worth checking before you assume a like-for-like oil swap is the cheaper route, because it can close most of the gap. The heat pump can cost less to run and cuts carbon, but it needs space, good insulation and often larger radiators. For an off-grid home with a failing boiler and a tight budget, a like-for-like oil replacement is the cheapest way to keep heating and hot water working.
Do I need a new oil tank when I replace the boiler?
Not always. If your tank is sound, bunded and the right distance from the boiler and any buildings, it can usually stay. An engineer will recommend replacing it if it is single-skin, over about 10 to 15 years old, cracked, or too close to a building under the fire rules. A new bunded oil tank supplied and fitted adds roughly £1,200 to £2,500, which is why a boiler-plus-tank job sits near the top of the range.
Can I fit an oil boiler myself?
No. Oil boiler work should be carried out by an OFTEC registered engineer, who commissions the boiler, sets the burner and notifies building control. Doing it yourself risks your home insurance, voids the manufacturer warranty, and can be dangerous if the combustion or oil supply is set up wrong. The only DIY part is choosing the boiler and keeping the area clear; the install has to be done by a registered engineer, which is why oil boilers are quoted supplied and fitted.
How long does an oil boiler installation take, and how often should it be serviced?
A like-for-like swap is usually a one-day job. A combi conversion, a relocation or a new tank stretches it to two or three days because of the extra pipework and commissioning. Once fitted, an oil boiler should be serviced every year by an OFTEC engineer, typically £120 to £150, which is a little more than a gas service because there is soot and a filter to clean. Annual servicing keeps the warranty valid and the boiler burning efficiently.
Check they are registered before they start
Oil-firing work is notifiable under the building regulations. A registered technician certifies their own work, which saves you a building control application and gives you the paperwork a buyer's solicitor asks for. Checking takes about a minute and it is free.
- Registered technician search OFTEC · OFTEC is the competent person scheme for oil-firing, so a registered technician can certify their own work instead of you applying to building control
Official guidance and sources
The rules and schemes referenced on this page come from these official UK sources. The price figures are Costwise's own; see how we price.
- Building regulations: Approved Document J GOV.UK · Part J covers combustion appliances and fuel storage, which is why fitting an oil boiler, its flue and its tank is notifiable building work.
Cite this data
These figures are free to use in articles, reports and research under a CC BY 4.0 licence. All we ask is a credit to Costwise, and online a link. Where your style allows, please make "Costwise" the linked word so readers can check the figure for their own region.
Costwise (2026): An oil boiler installation typically costs £3,500 in the UK, ranging from £2,600 to £6,000 supplied and fitted. Reviewed July 2026. costwiseuk.co.ukSource: Costwise (costwiseuk.co.uk)Costwise (2026). Oil boiler cost. Costwise UK cost data, version 2026-10-12. https://costwiseuk.co.uk/oil-boiler-cost/2026-10-12 (158 jobs)Dataset DOI: 10.5281/zenodo.21159943 · also on Kaggle, Hugging Face and Figshare. Method: how we price. Downloadable CSV.
These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing.