Oil Boiler Installation Cost in 2026 (UK)
A new oil boiler costs £2,500–£4,500 supplied and fitted in 2026 for a straight swap in the same position. Add a new oil tank and you are looking at £3,500–£6,000 all-in, and a full relocation or first-time oil system can reach £7,000+. Prices depend on the boiler type (regular, system or oil combi), the condition of your tank and pipework, and how much the flue and controls need reworking. Here is the full 2026 breakdown and the four things that move an oil boiler quote.
2026 oil boiler installation cost breakdown
| Job | Typical price (2026) | Time |
|---|---|---|
| Regular (heat-only) oil boiler — like-for-like swap | £2,500–£3,800 | 1 day |
| System oil boiler — like-for-like swap | £3,000–£4,200 | 1–1.5 days |
| Oil combi boiler — swap | £3,500–£4,500 | 1–2 days |
| New single-skin/bunded oil tank (supply & fit) | £1,000–£2,500 | 0.5–1 day |
| Boiler relocation (new flue & pipework) | +£600–£1,500 | +0.5–1 day |
| Full new oil system (boiler + tank + controls) | £5,000–£7,500 | 2–3 days |
Regular vs system vs oil combi
A regular (heat-only) oil boiler needs a feed tank and hot-water cylinder and suits older homes with existing tanks in the loft. A system boiler drops the loft tanks but keeps a cylinder, and is the most common oil replacement in 2026. An oil combi gives instant hot water with no cylinder, freeing up space, but costs more to buy and fit and suits smaller homes with one bathroom.
Do you also need a new oil tank?
Oil tanks last around 15–20 years. If yours is cracked, weeping, out of its bund, or fails an OFTEC inspection, budget £1,000–£2,500 for a replacement bunded tank. Fitting a new boiler onto a failing tank is a false economy — a leak can trigger an expensive pollution clean-up you are legally responsible for.
Four factors that move an oil boiler quote
1. Boiler type and output
Combi and higher-output boilers cost more than a basic heat-only unit. Match the output to the property rather than over-sizing.
2. Tank condition and position
A compliant, well-sited tank keeps the job simple; a tank that must be moved to meet fire-separation distances adds labour and materials.
3. Flue and relocation
Keeping the boiler where it is is cheapest. Moving it means new flue, oil supply line and condensate routing — often £600–£1,500 more.
4. Region and access
London and the South East sit at the top of the range; awkward access to the boiler or tank adds time on the day.
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