BOILERS GUIDE
New Boiler Cost 2026: Combi, System & Regular Pricing
A new boiler costs £2,000 to £4,500 fully installed in the UK in 2026, depending on the type and your home's setup.
Check eligibilityLast updated May 2026
A new boiler costs £2,000 to £4,500 fully installed in the UK in 2026, depending on the type and your home's setup.
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A new boiler costs £2,000 to £4,500 fully installed in the UK in 2026, depending on the type and your home's setup. Basic combi boilers start around £2,000 fitted. A high-spec system boiler or back boiler conversion can hit £4,500 or more. ECO4 can cover the full cost if you qualify, and other grants may take £500 to £1,500 off. Here's what really drives the price.
Some homeowners pay £1,950 for a like-for-like combi swap. Others get quoted £4,800 for what looks like the same job, on the same street, with the same boiler in the back of the van. The gap isn't always cowboy installers cutting corners. Most of it is boiler type, the spec, install complexity and what the quote genuinely includes versus what gets added later.
Here's roughly where 2026 quotes land by boiler type.
A genuine "fitted price" should include the boiler unit, the flue, the install labour, a Part L system flush and the commissioning paperwork. Building regs notification gets rolled in too, usually. If you've been quoted £2,400 with all of that included for a like-for-like combi swap in a normal two-bed semi, you're in a sensible mid-range for a mid-spec install. Not a bargain. Not a rip-off.
What gets billed on top, and what blindsides people: a power flush if the system is sludged up (£300 to £500), a magnetic filter retrofit if you don't already have one (£100 to £200), a smart thermostat upgrade (£100 to £300), new pipework if the boiler is being relocated to a different wall (£300 to £800). Each of these is a legitimate add-on. None should appear as a surprise on the final invoice after the job's been signed off.
There's also the difference between a "fitted price" and a "supply only" price. Most of the headline figures you see on installer websites and the big aggregator landing pages are supply only. The boiler in a box, on a pallet, ready for you to find someone to fit it. Adding installation takes the cost up another £700 to £1,500 depending on local labour rates. Worth confirming before you compare two quotes from different sources, because you're often not comparing the same thing.
Treat any boiler quote under £1,800 with suspicion. Either the unit is the cheapest in the brand range, the install is being rushed in half a day, or there's a separate upsell coming once the engineer's on site. The £2,500 to £3,500 zone is where most reputable independent installers genuinely operate, and that's the realistic budget for a normal swap on a normal house.
Type and brand do most of the heavy lifting. The rest matters more than installers usually let on at the survey.
Boiler brand. Worcester Bosch and Vaillant sit at the premium end, typically adding £200 to £600 over a mid-range equivalent. Baxi, Ideal and Alpha cover the reliable middle ground. Glow-worm and Vokera live at the budget end. A premium brand usually buys you a longer warranty (10 to 12 years versus 5 to 7) and better parts availability. It doesn't always buy you a quieter or more efficient boiler.
Output size in kW. Bigger isn't better. A 24 to 28kW combi handles most 2 or 3 bed homes comfortably. Pushing up to 35 or 40kW for a single-bathroom semi wastes money and runs less efficiently in part-load conditions. If an installer pushes a higher kW than your hot water demand actually needs, ask why before you sign.
Location of the boiler. Moving the boiler to a different wall is the single biggest hidden cost driver in a swap. New pipework, flue rerouting, sometimes a fresh hole through external brickwork. Easily £300 to £800 added on top of the base price. Like-for-like wall replacements stay at the lower end of the cost range.
Add-ons. A magnetic filter is effectively standard under Part L building regs. Some installers include it without itemising. Others list it separately, which makes their headline price look cheaper. A smart thermostat (Hive, Nest, Tado are the three you'll see quoted most often) adds £100 to £300 depending on the model and whether existing wiring works.
Power flush. If your existing system has any sludge or corrosion (typical on systems over 10 years old without a magnetic filter), Part L requires the new boiler to be commissioned on a clean system. That's another £300 to £500. Bizarrely, some discount installers skip this and void their own warranty in the process. Worth checking is in writing before the engineer arrives.
Where you live. London and the South East run 20 to 30% above the North East for the same job. Bristol and Edinburgh sit somewhere in the middle. A combi swap that costs £2,200 in Newcastle quotes £2,900 in Wimbledon. Same boiler, same labour hours, different postcode.
The seventh is switching brands. Going from a Worcester to an Ideal sometimes adds £100 to £300 in installer familiarity premium, especially if the engineer is more comfortable with one brand's quirks. Worth asking. Worth not paying if it isn't actually justified.
This is the bit most cost guides skim past. Three live national routes matter in 2026.
ECO4 covers the full cost of a replacement if you qualify. Eligibility hinges on two things. First: whether someone in the household receives a qualifying benefit (Universal Credit, Pension Credit, Income Support and several others). Second: whether the home has an EPC rating of D or below. According to GOV.UK guidance on ECO4, the scheme is funded by the major energy suppliers (British Gas, OVO, EDF, Octopus, E.ON, Scottish Power) and runs until December 2026. It's the only scheme that covers 100% of boiler costs in 2026, and most people we hear from don't realise they qualify until they actually run the eligibility check.
The Boiler Upgrade Scheme doesn't cover gas boilers at all. It gives you £7,500 off a heat pump installation instead. Worth knowing if you're at a decision point on heating type, because the maths sometimes flips the answer. If your home is properly insulated and you'd otherwise spend £4,000 on a new gas boiler, a heat pump at around £8,000 after the BUS grant is genuinely competitive on five-year running costs. Not always the right call, but more often than people assume. See our heat pump cost guide for the running cost detail.
Some councils run their own Warm Homes Local Grant schemes that include boiler upgrades. Others restrict to insulation only. Sheffield and Cornwall councils have both included boiler measures in recent rounds. Manchester has not. The funding gets allocated to local authorities and how each one chooses to deploy it varies year on year. The council website is the only reliable source for what's actually live in your area today.
If anyone in the household is a pensioner, the ECO4 route through Pension Credit catches more households than people expect. We cover that route specifically in our pensioner boiler grants guide. The "free boilers for over 60s" framing you see on Facebook ads isn't quite accurate. Age alone doesn't qualify. The underlying scheme often does, which is a different and more useful thing to know.
Most cost guides treat grants as a footnote. They shouldn't be. If you qualify for ECO4, the headline cost is zero. If you don't, the right grant route can still take £500 to £1,500 off a private install.
Three quotes minimum, from Gas Safe or MCS-certified installers. The certification matters more than the price difference. Anyone fitting a gas boiler without Gas Safe registration is breaking the law, and your warranty becomes worthless the moment something goes wrong. The Gas Safe Register lets you check any engineer's ID number in a few seconds before you let them on site.
Get the quote itemised. Unit cost, labour, parts, VAT separated. If an installer refuses to break it down, that's a red flag worth walking away from.
The "from £X" language on website headlines is almost always quoted for the cheapest unit in the cheapest property type. Real quotes come after a home visit or a video survey, not from a postcode-and-name comparison form. A reasonable turnaround is 24 to 48 hours after the survey, not a doorstep figure pressured into a signature.
Watch for "today only" pricing. Gas boilers don't go on sale, and reputable installers don't pressure decisions during the survey itself. The £2,800 quote today will still be £2,800 next week. Anyway, the urgency is almost always manufactured.
A working 10-year-old boiler isn't usually worth replacing on efficiency grounds alone. Modern condensing boilers are 90 to 94% efficient versus 70 to 80% for an older non-condensing predecessor, but the real-world saving works out to maybe £100 to £200 a year on a typical heating bill. Payback on a £3,000 install runs 15 to 30 years, which is longer than the boiler is likely to last anyway. The Energy Saving Trust puts the figure in a similar range.
Boilers over 15 years old are a different conversation. Efficiency drops 20 to 30% versus modern equivalents. Breakdown risk climbs sharply. Parts get harder to source as manufacturers retire spares from older ranges. If yours falls in this bracket, plan the replacement before it fails on the coldest week in February.
The 2026 gas boiler ban for new builds doesn't apply to existing homes replacing like-for-like. You're not racing a regulatory clock on a swap.
Honest position: don't replace a working boiler chasing efficiency gains. Replace when it fails, or when the annual repair bill is hitting 50% of a new install. The exception is when you're already qualifying for ECO4. At that point the boiler is free anyway and the calculation flips.
Open the eligibility checker before you sign a quote. Two minutes. If ECO4 covers your home, the £3,000 you were about to spend stays in your account. If it doesn't, you'll still see which other grants apply, and which questions to ask your installer before the engineer arrives.
For the wider picture on boiler grants and options, the boilers hub collects everything we've published on the topic in one place.
Common questions