Supplied and fitted, varies by type and brand
Median like-for-like quote in early 2026
Same-spot combi swap is cheapest; conversions cost most
Boiler Upgrade Scheme for an air source heat pump instead
How much does boiler replacement cost in 2026?
Prices below reflect supplied-and-fitted costs for a typical 3-bed UK home in 2026, based on recent installer quotes. The single biggest variable is whether you stay with the same boiler type in the same location, or change type, move the unit, or add a cylinder.
| Job type | Typical 2026 range | Notes |
|---|---|---|
| Like-for-like combi swap (same spot) | £1,800–£3,000 | Cheapest job; budget A-rated unit at the low end |
| Mid-range combi (Worcester/Vaillant/Ideal) | £2,000–£3,200 | 30kW unit, 3-bed home, same position |
| Premium combi with long warranty | £2,800–£3,900 | Top-tier unit plus filter and controls |
| System boiler + new cylinder | £3,800–£5,500 | Adds unvented cylinder and extra pipework |
| Regular (heat-only) boiler swap | £2,300–£3,500 | Keeps tanks and cylinder |
| Convert regular/system to combi | £3,000–£4,500 | Removes tanks and cylinder, re-runs pipework |
| Boiler relocation (add-on) | +£300–£800 | New gas, water and flue routing |
| Air source heat pump (alternative) | £7,000–£14,000 | Before the £7,500 grant is deducted |
What affects the cost
Two boilers with the same badge can be hundreds of pounds apart once the job is factored in. The big drivers are:
- Boiler type: combi units are cheapest to fit; system and regular boilers add a cylinder and tanks, and conversions add removal work.
- Same spot vs relocation: keeping the boiler where it is avoids new gas runs, pipework and a fresh flue core — moving it adds £300–£800.
- Brand and warranty tier: a budget Ideal Logic sits below a Worcester Greenstar or Vaillant ecoTEC, and longer warranties usually mean a higher unit price.
- Output (kW): larger homes with multiple bathrooms need higher-output combis or a system boiler, which cost more.
- System condition: sludgy radiators may need a power flush, and most manufacturers insist on a magnetic filter to honour the warranty.
- Region: London and the South East typically run 10–20% above the national average.
Cost breakdown: boiler vs labour vs extras
On a typical combi swap the unit itself is roughly £700–£1,900 at trade price, with the rest going on labour, controls and sundries. A two-person crew usually completes a like-for-like combi in a day, so labour on a straightforward job is often £500–£900.
- Boiler unit: £700–£1,900 depending on brand and output.
- Labour: £500–£900 for a one-day swap; £900–£1,500 for a 2–3 day conversion or relocation.
- Magnetic filter (e.g. MagnaClean): £80–£150 fitted — often mandatory for warranty.
- Power flush or chemical clean: £300–£650 if the system is dirty.
- Controls/smart thermostat: £100–£250 if upgraded.
Budget vs mid-range vs premium brands
Brand choice is mostly about warranty length, noise and resale recognition rather than basic performance.
- Budget (Ideal Logic Max): typically £300–£500 cheaper like-for-like, fitted around £2,000–£2,800. Solid, well-supported and the value pick.
- Mid to premium (Worcester Bosch Greenstar): the most widely installed brand with strong resale recognition and a large installer network; fitted £2,200–£3,800.
- Premium (Vaillant ecoTEC): known for quiet running and up to a 12-year warranty via accredited installers; fitted £2,300–£3,900.
Paying for a brand is reasonable, but don't pay premium money for a budget unit — check the exact model on the quote.
Common extras and hidden costs
The headline price often isn't the final price. Watch for these add-ons:
- Relocation: +£300–£800 for new pipework and flue.
- Conversion to combi: +£500–£1,500 on top of the boiler to strip out tanks and cylinder.
- Power flush: £300–£650 — only essential if there's sludge, cold radiator patches or noisy circulation.
- New flue, condensate run or gas pipe upgrade: can add a few hundred pounds if the existing setup isn't compliant.
- Scaffolding: occasionally needed for high or awkward flue work.
- Making good: tiling, plastering or boxing-in after pipework changes.
How to save money without cutting corners
The biggest savings come from the job, not from skimping on the boiler.
- Stay like-for-like and in the same spot — it's by far the cheapest route.
- Get three written quotes naming the same make, model and output so you're comparing like with like.
- Pick the right size, not the biggest — an oversized boiler costs more to buy and run.
- Use a fixed-price online installer for simple swaps; they're often cheaper than big-name brands like British Gas.
- Question an unnecessary power flush — it's not always needed.
- Time it before winter when engineers are quieter and more willing to negotiate.
The heat pump alternative and the Boiler Upgrade Scheme
If your boiler is on its last legs, it's worth at least pricing an air source heat pump before defaulting to gas. The Boiler Upgrade Scheme in England and Wales gives a £7,500 grant towards an air or ground source heat pump replacing a fossil-fuel or non-heat-pump electric system. There's no income test and no insulation requirement as of 2026, and from 21 July 2026 a temporary uplift to £9,000 applies to eligible oil and LPG homes.
Your installer must be MCS-certified and a member of an approved consumer code (such as RECC or HIES); they apply for the grant and deduct it from your quote, so you pay only the net amount. Heat pumps cost roughly £7,000–£14,000 before the grant, suit well-insulated homes best, and run on electricity rather than gas — a bigger upfront decision than a like-for-like boiler swap, but one the grant can make competitive.
Signs you need a new boiler
A boiler near the end of its life often warns you first. Consider replacement if you notice:
- Frequent breakdowns or repairs costing more than half the price of a new unit.
- Age over 12–15 years — efficiency drops and parts get scarce.
- Rising gas bills with no change in usage.
- Persistent low pressure, leaks or a yellow (not blue) flame — the last is a safety red flag; turn it off and call a Gas Safe engineer.
- Banging, gurgling or kettling noises from the boiler or radiators.
Regional price differences (2026)
Where you live still moves the price in 2026, mainly through labour rates. London and the South East sit above the rest of the country; the North, Scotland and Wales are typically cheaper.
| Region | Typical 2026 range |
|---|---|
| London | £2,400–£5,000 |
| South East | £2,200–£4,500 |
| Midlands | £1,900–£3,800 |
| North of England | £1,800–£3,600 |
| Scotland & Wales | £1,800–£3,500 |
Cost estimator
Estimate a ballpark boiler replacement cost based on your boiler type, brand tier and the complexity of the job.
This estimate is a budgeting tool, not a quote. Real prices vary — get local quotes for an accurate figure.
Get real quotesHow to save money
- Stay like-for-like and keep the boiler in its existing position to avoid relocation and conversion costs.
- Get at least three written quotes that name the same make, model and kW output.
- Choose a correctly sized boiler rather than the biggest — oversizing wastes money upfront and on running costs.
- Use a fixed-price online installer for simple combi swaps; they often undercut big-brand engineers.
- Don't pay for a power flush unless there's real evidence of sludge or cold spots.
- Book in spring or summer when heating engineers are less busy and more open to negotiation.
- Check whether an air source heat pump and the £7,500 grant make the long-term sums work before committing to gas.
- Register your warranty promptly and keep annual services to protect it.
How long it takes
- Survey and quote: 30–60 minutes, often free.
- Like-for-like combi swap: 1 day.
- System boiler with cylinder, conversion or relocation: 2–3 days.
- Commissioning, Gas Safe registration and Building Regs notification: same day as install.
- Heat pump installation (alternative): typically 2–5 days.
What's usually included
- Removal and safe disposal of the old boiler
- Supply and fitting of the new boiler and flue
- Standard connection to existing gas, water and heating pipework
- Commissioning, safety checks and Gas Safe / Building Regs registration
- Basic system controls and manufacturer warranty registration
- A magnetic filter where required for the warranty
What's usually extra
- Moving the boiler to a new location
- Converting from a regular/system boiler to a combi
- Power flushing a heavily sludged system
- New or upgraded radiators and thermostatic valves
- Upgrading the incoming gas supply pipe if undersized
- Making good (tiling, plastering, boxing-in) after pipework changes
How to choose the right heating engineers
Any engineer working on a gas boiler must be on the Gas Safe Register by law — check the card and the register before work starts. A good installer also explains options clearly and quotes the exact model in writing.
- Confirm the engineer is Gas Safe registered and check their ID card number on gassaferegister.co.uk.
- Get the exact make, model and kW output named on a written, itemised quote.
- Ask whether the price is fixed or could change once work begins.
- Check the manufacturer warranty length and that the installer is accredited to offer it.
- Ask if a power flush or magnetic filter is genuinely needed and why.
- Confirm the job includes Building Regulations notification and a benchmark/commissioning certificate.
- Read recent reviews and ask for references from local jobs.
- For a heat pump, check the installer is MCS-certified and a member of an approved consumer code (RECC or HIES).
Boiler replacement cost FAQs
How much does a new boiler cost in the UK in 2026?
Most replacements cost £1,800–£4,500 supplied and fitted. A like-for-like combi swap is typically £1,800–£3,000, while a system boiler with a cylinder or a full conversion can reach £4,000–£5,500.
Is a combi cheaper than a system boiler?
Yes. A combi has no separate cylinder or tanks, so a like-for-like combi swap is the cheapest job. A system boiler adds a cylinder and pipework, pushing the price to £3,800–£5,500.
Which boiler brand is best value?
Ideal Logic Max is usually the cheapest like-for-like, often £300–£500 less than rivals. Worcester Bosch offers the widest installer network and strong resale recognition, while Vaillant is prized for quiet running and a 12-year warranty via accredited fitters.
How much does it cost to move a boiler?
Relocating a boiler typically adds £300–£800 because it needs new gas, water and heating pipework plus a fresh flue core hole. Moving it far (e.g. to a loft or garage) sits at the top of that range.
How long does a boiler replacement take?
A like-for-like combi swap usually takes one day. A system boiler with a cylinder, a conversion or a relocation typically takes 2–3 days.
Do I need a power flush with a new boiler?
Not always. A power flush (£300–£650) is only essential where there's sludge, cold radiator patches or noisy circulation. Many manufacturers require at least a chemical clean and a magnetic filter to validate the warranty.
What is the Boiler Upgrade Scheme?
It's a government grant in England and Wales of £7,500 towards an air or ground source heat pump replacing a fossil-fuel or electric system. There's no income or insulation test in 2026, and from 21 July 2026 eligible oil and LPG homes can get £9,000. Your MCS-certified installer applies and deducts it from your quote.
Should I get a heat pump instead of a new boiler?
It's worth pricing one if your home is reasonably well insulated. With the £7,500 grant, a heat pump (£7,000–£14,000 before the grant) can become competitive, runs on electricity and cuts carbon — but it's a bigger decision than a like-for-like gas swap.
Does my installer need to be Gas Safe registered?
Yes, by law. Anyone working on a gas boiler must be on the Gas Safe Register. Always check their ID card and verify the number on gassaferegister.co.uk before work starts.
Why are prices higher in London?
Mainly labour rates. London and the South East typically run 10–20% above the national average, while the North, Scotland and Wales tend to be cheapest.