How Much Does a New Boiler Cost in 2026?
The average cost of a new boiler in the UK sits between £1,500 and £3,500 fully installed. A straightforward like-for-like swap is at the lower end, while switching boiler types or moving to a new location pushes the price higher. The final bill depends on the brand you choose, your existing setup, and where you live.
£2,100
Average cost
£1,500
Lowest price
£3,500+
Premium install
1–2 days
Installation time
Prices updated April 2026 · Based on industry data and contractor submissions.
Gas Safe registered engineers only. It is illegal to work on gas appliances without being registered with the Gas Safe Register. All installations must comply with Building Regulations Part J and be recorded on the Benchmark Commissioning Certificate. Always check your engineer's registration before any work begins.
New Boiler Prices at a Glance
Prices below are for supply and installation of a new combi boiler in an average UK home, swapping like-for-like in the same location.
Combi boiler
Best for flats and small to medium homes
£1,500 – £3,500
System boiler
Suited to homes with 2+ bathrooms
£2,000 – £4,500
Heat-only boiler
Replacing an older conventional system
£2,500 – £5,000
Combi Boiler Prices by Brand Tier
| Boiler Type | Average Cost | Price Range |
|---|---|---|
| Budget combi (e.g., Baxi 600, Ideal Logic) | £2,000 | £1,500 – £2,400 |
| Mid-range combi (e.g., Worcester Bosch Greenstar) | £2,700 | £2,200 – £3,100 |
| Premium combi (e.g., Vaillant ecoTEC, Viessmann) | £3,200 | £2,800 – £3,800 |
Prices include supply, installation, flue, and commissioning. Excludes power flush, new pipework runs, or system upgrades.
Boiler Prices by Brand
Not all boilers are created equal. Here's what you can expect to pay for the most popular brands in the UK, fully installed.
| Brand | Price Installed |
|---|---|
| Worcester Bosch | £2,400–£2,900 |
| Vaillant | £2,500–£3,100 |
| Ideal | £1,600–£2,100 |
| Baxi | £1,800–£2,300 |
| Viessmann | £2,200–£2,700 |
Prices shown are for supply and installation of a combi boiler in a standard setup. See our British Gas price comparison for a look at how national installers stack up against local engineers.
What Size Boiler Do I Need?
Getting the right output for your property is one of the most important decisions. Too small and you'll struggle with hot water; too large and you're wasting money on a boiler you don't need. Here's a rough guide - your engineer will do a proper heat-loss calculation during the survey.
| Property | Recommended Output | Typical Cost |
|---|---|---|
| Small flat | 24–28 kW combi | £1,500–£2,200 |
| Mid terrace | 28–32 kW combi | £1,800–£2,600 |
| Semi-detached | 30–35 kW combi | £2,000–£3,000 |
| Detached | 35–40 kW system | £2,500–£3,500 |
| Large detached | 35–40 kW system | £3,000–£4,500 |
Good to know: If you have two or more bathrooms used at the same time, a system boiler with a hot water cylinder will usually perform better than a combi. Combis can struggle to deliver decent flow to two showers running simultaneously.
What Affects the Cost of a New Boiler?
Boiler type and brand
This is the biggest single factor. A budget Baxi combi installed is around £1,800. The equivalent Worcester Bosch Greenstar - considered the gold standard by most heating engineers - runs closer to £2,700. Premium German brands like Vaillant and Viessmann command £3,000+. The quality difference is real, though - Worcester Bosch and Vaillant boilers regularly outlast cheaper alternatives by several years.
Like-for-like swap vs. conversion
Swapping an old combi for a new combi in the same spot is the quickest and cheapest option. Converting from a heat-only system to a combi means removing your cylinder and cold water tank, running new pipework, and potentially balancing radiators - add £400–£1,000 to the job.
Your existing system's condition
If your radiators, pipework, or system controls are old, engineers may recommend - or require - additional work. A power flush (£300–£600) clears sludge that can shorten a new boiler's life. New thermostatic radiator valves (TRVs) and a smart thermostat can add £300–£500 but significantly improve efficiency.
Flue routing and location
Standard horizontal flue through an external wall: no extra charge. Longer flue runs, vertical flue through a roof, or moving the boiler to a different location can add £150–£500. High-rise flat installations or any job requiring scaffolding for the flue add further cost.
Location
Labour costs vary significantly across the UK. London heating engineers charge 20–30% more than the national average. Northern England and Scotland typically come in 5–10% below average. See our regional breakdown below.
Additional and Hidden Costs
The headline installation price rarely tells the full story. Here's what can push the final bill up - and what's actually worth paying for.
| Extra Item | Typical Cost |
|---|---|
| Power flush | £300 – £600 |
| Magnetic system filter (e.g., Magnaclean) | £100 – £200 |
| Smart thermostat (Nest, Hive, tado°) | £130 – £250 |
| Thermostatic radiator valves (per radiator) | £25 – £50 each |
| Annual boiler service plan | £80 – £150/year |
| Removal of old boiler and system components | £100 – £300 |
| Building Regulations compliance certificate | Usually included |
Considering underfloor heating?
If you're fitting a new boiler, it's worth thinking about underfloor heating at the same time. Modern condensing boilers run most efficiently at lower flow temperatures - exactly what underfloor systems need. Retrofitting later means draining the system and lifting floors, so doing it now saves both hassle and money.
Boiler Running Costs and Efficiency
The purchase price is only half the picture. An inefficient old boiler can cost you hundreds more per year in gas than a modern replacement - and that adds up fast.
Old G-rated boiler (70% efficient)
~£1,200/year gas bill for an average 3-bed
New A-rated boiler (92%+ efficient)
~£850/year gas bill for the same house
Annual saving: £200–£350
Swapping an old G-rated boiler for a new A-rated model typically saves between £200 and £350 a year on gas. The exact figure depends on your home's insulation, how much heating you use, and current gas prices.
Payback period: 5–10 years
At £250/year in savings against a £2,000 boiler cost, you're looking at roughly 8 years to break even. A more expensive boiler takes longer, but you also get better reliability and warranty cover during that time.
What does A-rated mean? Under the ErP (Energy-related Products) labelling system, an A-rated boiler converts at least 92% of the gas it burns into usable heat. Old boilers rated G or F waste 25–30% of every pound you spend on gas - literally sending money up the flue.
When Should You Replace Your Boiler?
Not every boiler problem means you need a new one. But there are some clear signs that replacement makes more sense than another repair.
Over 12 years old
Even well-maintained boilers lose efficiency with age. Parts become harder to source after 10–12 years.
Needing repairs more than once a year
Frequent breakdowns are a sign the boiler is on its way out. The repair costs soon add up.
Energy bills climbing despite similar usage
If your gas bill keeps rising but your habits haven't changed, your boiler's efficiency has likely dropped.
Uneven heating or slow hot water recovery
Rooms not heating properly or long waits for hot water suggest the boiler can't keep up with demand.
Parts becoming difficult to source
Once manufacturers stop making parts for your model, repair costs jump and wait times stretch out.
Yellow or orange flame instead of blue
This is urgent - it can indicate incomplete combustion and possible carbon monoxide risk. Switch the boiler off and call a Gas Safe engineer immediately.
Repair or Replace?
A simple rule of thumb: if your boiler is under 8 years old and the repair costs less than £500, it's usually worth fixing. If it's over 12 years oldor you're facing a repair bill over £500, replacement is almost always more cost-effective in the long run.
For boilers aged 8–12 years, it depends on the specific fault and general condition. Get a few quotes for both repair and replacement so you can compare properly.
Electric Boiler Cost
If your property doesn't have a gas supply - or you'd rather avoid gas altogether - an electric boiler is worth a look. They're smaller, quieter, and simpler to install than gas boilers. The catch? Running costs are significantly higher unless you've got solar panels offsetting your electricity bill.
Electric Boiler Prices (Installed)
Electric combi boiler
Heats water on demand, no cylinder needed
£1,500 – £2,500
Electric system boiler
Works with a hot water cylinder for higher demand
£1,800 – £3,000
Electric flow boiler
Compact, lower output - suits small flats
£1,000 – £2,000
Electric vs Gas Boiler: How They Compare
| Factor | Electric Boiler | Gas Boiler |
|---|---|---|
| Installation cost | £1,000 – £3,000 | £1,500 – £3,500 |
| Annual running cost | £1,200 – £1,800 | £600 – £900 |
| Efficiency | 99–100% | 90–94% |
| Annual maintenance | £50 – £80 | £80 – £150 |
| Typical lifespan | 10–15 years | 10–15 years |
The numbers tell the story: electric boilers are cheaper to buy and install, but roughly three times more expensive to run. Electricity costs around 24p per kWh compared to about 7p per kWh for gas - so even though electric boilers are 99–100% efficient at point of use (versus 90–94% for gas), the fuel cost difference wipes out that advantage entirely.
When electric makes sense
- No mains gas supply (off-grid properties)
- Flats where running a gas flue is difficult or not permitted
- New builds with solar panels (electricity is essentially free)
- Small properties with low heating demand
When it doesn't
- Large homes with high hot water demand
- Properties without solar panels (the bills will be painful)
- Homes with mains gas already connected
Key electric boiler brands
The electric boiler market is smaller than gas, but there are a few well-regarded names. Elnur Mattira is probably the most popular in the UK - compact, reliable, and well-suited to flats. Heatrae Sadia Electromax is a combined boiler and hot water cylinder in one unit, good for properties with slightly higher demand. Electric Heating Company Comet is another solid option, particularly for smaller homes.
Installation note: Electric boilers don't require a Gas Safe registered engineer, but they should always be installed by a qualified electrician who is Part P compliant (registered with a competent person scheme like NICEIC or NAPIT). This ensures the work meets Building Regulations and is properly certified.
New Boiler Prices by Region
Where you live has a real impact on what you'll pay. These are average installed prices for a mid-range combi boiler in each region.
| Region | Average Cost | vs National |
|---|---|---|
| London | £2,600 | +25% |
| South East | £2,300 | +10% |
| East of England | £2,200 | +5% |
| South West | £2,150 | +3% |
| Midlands | £2,080 | Average |
| Yorkshire | £1,950 | -6% |
| North West | £1,950 | -6% |
| North East | £1,880 | -10% |
| Scotland | £1,950 | -6% |
| Wales | £1,990 | -4% |
Based on industry data. Prices for a mid-range combi boiler swap, fully installed.
How to Get Your New Boiler for Less
A few smart moves can easily save you £300–£700 on the total bill - without cutting corners on quality.
Book in spring or summer
Heating engineers are busiest October to January. Book your replacement in April, May, or June and many engineers will offer better rates simply because they have more availability. You can also take your time getting quotes rather than being pressured by a broken boiler in winter.
Get at least three quotes
Prices for the same boiler can vary by £500 or more between engineers in the same area. Use a comparison service like this one to get free quotes from multiple Gas Safe engineers near you. The cheapest isn't always the best - check reviews and warranties too.
Check if you qualify for a free boiler
The government's ECO4 scheme provides free or heavily subsidised boilers to households on certain benefits, including Universal Credit, Pension Credit, and child tax credits. If you qualify, the boiler itself is typically free - worth £2,000+ in saved costs. Check eligibility at gov.uk or ask your energy supplier.
Don't always go for the cheapest brand
Budget boilers have higher failure rates and shorter warranties (typically 2–5 years). Worcester Bosch and Vaillant cost more upfront but come with 8–12 year warranties and lower long-term repair costs. Over a 10-year period, a mid-range boiler often works out cheaper than a budget one.
Bundle work to save on labour
If you need new radiators, TRVs, or a power flush, get them done at the same time as your boiler install. Engineers will often reduce the labour rate for additional work carried out in the same visit.
Explore manufacturer finance
Worcester Bosch, Vaillant, and Baxi all offer 0% or low-interest finance through their installer networks. If you need a premium boiler but can't fund it upfront, this can make a big difference - just check the total repayable amount carefully.
What to Expect: The Boiler Installation Process
A standard boiler swap is a well-trodden job for any experienced heating engineer. Here's roughly how it goes.
- 1
Survey and quote
A reputable engineer will visit to assess your existing system before quoting. They'll check the boiler location, flue route, gas supply, and pipework condition. Be wary of any engineer happy to quote without seeing the property.
- 2
Day 1: Drain down and removal
The engineer drains the system, disconnects the old boiler, and removes it. For a system-to-combi conversion, this also means decommissioning the hot water cylinder and cold water tank.
- 3
Installation
The new boiler is fitted, the flue is run, and the pipework is connected. This is also when any additional work (magnetic filter, TRVs, thermostat) is carried out.
- 4
Pressure test and commission
The system is refilled, pressure-tested, and the boiler is commissioned (set up and started for the first time). A properly commissioned boiler runs a full heating cycle to check all zones work correctly.
- 5
Benchmark certificate and Building Regs notification
You'll receive a Benchmark Commissioning Certificate - keep this safe as it's required for warranty claims. Your engineer notifies Building Control as required by law, and you'll get a completion certificate.
- 6
Handover and instructions
A good engineer will walk you through the new controls, explain how to repressurise the system if needed, and leave you with all documentation including warranty registration details.
Frequently Asked Questions
How much does a new boiler cost in the UK?
A new boiler typically costs between £1,500 and £3,500 fully installed in the UK. The exact price depends on the boiler type (combi, system, or heat-only), the brand, and your location. Budget combi boilers start from around £1,500 installed, while premium models from Worcester Bosch or Vaillant can reach £3,500 or more.
How long does a boiler installation take?
A straight boiler swap - replacing a like-for-like boiler in the same location - usually takes one full day. If you're switching boiler types (for example, from a heat-only to a combi), or moving the boiler to a new location, the job can take two to three days.
Do I need planning permission to replace my boiler?
No planning permission is required for a standard boiler replacement. However, the installation must comply with Building Regulations Part J, and the work must be carried out by a Gas Safe registered engineer. Your installer will notify Building Control and issue a Benchmark Commissioning Certificate on completion.
What is the best boiler brand in the UK?
Worcester Bosch consistently tops reliability surveys and is the most installed brand in the UK - their Greenstar range comes with an 8–12 year warranty on most models. Vaillant is a close second, particularly in larger homes. For mid-range value, Ideal and Baxi are solid choices, though their warranties are typically shorter (5–7 years).
Can I get a free boiler?
You may qualify for a free or heavily subsidised boiler through the government's ECO4 scheme if you're on certain benefits (Universal Credit, Pension Credit, child tax credits, etc.) or live in a low-income household. The Boiler Upgrade Scheme offers a £7,500 grant towards an air source heat pump instead of a gas boiler.
How long should a boiler last?
A well-maintained gas boiler should last 10–15 years. Annual servicing is the single biggest factor in longevity - a boiler that's serviced every year will consistently outlast one that isn't. If your boiler is over 12 years old and requiring regular repairs, replacement is usually more cost-effective.
What's the difference between a combi, system, and heat-only boiler?
A combi (combination) boiler heats water on demand - no hot water cylinder needed. It's ideal for flats and smaller homes with 1–2 bathrooms. A system boiler works with a hot water cylinder but no cold water tank, suiting homes with higher hot water demand. A heat-only (regular or conventional) boiler requires both a cold water tank and a hot water cylinder - best for older properties with existing systems.
How much does an electric boiler cost?
An electric combi boiler costs £1,500–£2,500 installed, while electric system boilers run £1,800–£3,000. They're cheaper to install than gas boilers and are 99–100% efficient, but electricity costs roughly three times more per kWh than gas - so annual running costs are typically £1,200–£1,800 compared to £600–£900 for gas. Electric boilers make most sense for off-grid properties, flats without gas flues, or homes with solar panels.
Should I replace my gas boiler with a heat pump?
Heat pumps can cut long-term running costs, but they require a well-insulated home and cost significantly more upfront (£8,000–£15,000 installed, though the £7,500 Boiler Upgrade Scheme grant helps). If your home is well-insulated and you're planning a long-term stay, it's worth getting a heat pump assessment alongside boiler quotes.
Written by James Carter, Less.co.uk energy specialist
Last updated: · Pricing based on industry data and verified contractor submissions · Methodology
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