When your boiler breaks, it can become a serious problem quickly - especially in winter. Fortunately, replacing it no longer has to involve several home visits, vague estimates and weeks of waiting.
With Heatable, you can answer a few questions online, compare suitable boilers and get a fixed price that includes installation.
In many areas, your new boiler can be fitted as soon as the next day when you book before 3pm, subject to availability.
🔑 Key Points:
A replacement boiler typically costs £1,800 to £3,500, including installation.
A straightforward like-for-like swap usually takes one day.
Relocating a boiler or changing the system type normally takes one to two days.
Heatable prices include the boiler, installation essentials, VAT and aftercare.
Selected boilers include manufacturer guarantees of up to 10 years.
Up to four years at 0% APR is available on selected packages, subject to status.
How much does a replacement boiler cost?
Most replacement boiler installations cost between £1,800 and £3,500. A simple combi-for-combi swap sits at the lower end, while moving the boiler or converting the heating system costs more.
Installation type | Typical cost | Typical time |
Combi boiler replacement | £1,800–£2,800 | 1 day |
Regular or system boiler replacement | £2,000–£2,800 | 1 day |
Regular-to-combi conversion | £2,600–£3,500 | 1-2 days |
Boiler relocation | Priced for the job | 1-2 days |
These are guide prices, not quotations. The Energy Saving Trust estimates that replacing a G-rated gas boiler with an A-rated boiler and thermostatic radiator valves costs an average of £3,500 in Great Britain.
Your price will depend on:
the boiler brand, model and output
whether the replacement is like for like
whether the boiler is moving
flue, pipework and access requirements
controls and optional system upgrades
Explore the costs: Read our complete new boiler cost guide
Should you repair or replace your boiler?
Not every fault means you need a new boiler. Repair may make sense if the appliance is relatively young, has previously been reliable and remains under its manufacturer’s guarantee.
Replacement may be better value when:
the boiler is around 10 to 15 years old
breakdowns are becoming frequent
parts are expensive or difficult to find
an engineer says it is beyond economical repair
it no longer meets your heating or hot-water needs
you are renovating or moving the boiler anyway
Compare the repair price with the installed cost, efficiency and guarantee of a replacement. One expensive repair can be poor value if an older boiler is likely to develop another fault.
Never remove the boiler casing or attempt gas work yourself. If you smell gas, call the National Gas Emergency Service on 0800 111 999.
Which type of boiler do you need?
You do not always have to replace like for like. The right choice depends on your hot-water demand, available space, mains water pressure and existing heating system.
Boiler type | Usually best for | Key consideration |
Combi | Smaller and medium homes, often with one bathroom | Compact and supplies hot water on demand, but may struggle with several outlets at once |
System | Homes with multiple bathrooms | Supplies stored hot water to several outlets but needs a cylinder |
Regular | Larger homes and older heating systems | Works with a cylinder and usually loft tanks, so needs more space |
Keeping the same boiler type is generally the simplest and least expensive option. A conversion may be worthwhile if your household’s needs have changed, but it requires more pipework and labour.
Compare your options: Read our guide to combi, system and regular boilers
Boiler Replacement - What's included in your new boiler installation?
What size boiler do you need?
Boiler size means heat output in kilowatts (kW), not the physical dimensions of the appliance.
For combi boilers, an installer considers both heating demand and the hot-water flow you need.
For system and regular boilers, the property’s heat loss and hot-water cylinder are important.
The number of bedrooms or radiators can provide a starting point, but it should not be used alone to select a boiler.
Choosing a boiler that is too small can leave it struggling. Choosing one that is unnecessarily powerful can cost more and may operate less efficiently.
Find the right output: Read our complete boiler size guide
What is included in a Heatable installation?
A standard Heatable boiler installation includes:
your chosen boiler and required flue accessories
installation by a Gas Safe registered engineer
standard parts and pipework
a system flush, inhibitor and magnetic filter
compliant controls where required
removal and recycling of the old boiler
manufacturer guarantee registration and relevant paperwork
VAT
Heatable aftercare and a 12-month workmanship warranty
The exact scope depends on your installation. Your fixed quote will clearly show what is included and identify any optional upgrades.
How long does boiler installation take?
A like-for-like boiler replacement in the same location normally takes one day. Moving the boiler or converting from a regular boiler to a combi usually takes one to two days.
Before installation, Heatable will ask for photos of your current setup. This helps confirm the work and materials required.
On the day, the engineer will remove the old boiler, fit and test the replacement, commission the system and explain the controls.
Your heating and water will be unavailable for part of the installation, so clear the work area and make sure the engineer can reach the boiler, meters, controls and relevant tanks or cylinder.
Plan for installation day: [Read our step-by-step boiler installation guide]
Will a new boiler reduce your energy bills?
It can, particularly when an old non-condensing boiler is replaced with a modern condensing model.
Your actual saving depends on the old boiler’s efficiency, your home, energy tariff, controls and heating habits.
Correct sizing and good controls matter.
A smart thermostat, weather or load compensation and suitable flow temperatures can help the heating system operate more efficiently.
Treat “save up to” figures as examples rather than guarantees. Replacing one modern condensing boiler with another may produce a much smaller saving than replacing an old G-rated appliance.
Can you pay monthly for a replacement boiler?
Yes. Heatable offers payment in full, interest-bearing finance and up to four years at 0% APR on selected boiler packages.
Finance is subject to status and lender approval. An interest-bearing agreement increases the total amount repaid, so compare the APR, term, monthly payment and total payable - not only the monthly figure. Available options will be shown with your quote.
Compare payment options: Read our boiler finance guide
Are boiler replacement grants available?
The ECO4 scheme supports energy-efficiency measures for some low-income, fuel-poor and vulnerable households in Great Britain.
Depending on eligibility and the property assessment, this can include heating-system repairs or upgrades. ECO4 is due to run until 31 December 2026.
The Boiler Upgrade Scheme does not fund replacement gas boilers. It supports eligible low-carbon systems in England and Wales, including heat pumps and, in limited circumstances, biomass boilers. Current grants range from £2,500 to £9,000 depending on the technology and property.
Eligibility rules apply and schemes can change. Check the current official guidance before making a decision.
Check available help: Read our guide to boiler grants and heating schemes
Why choose Heatable?
Get a fixed price online without a sales visit.
Choose from boilers matched to your home and budget.
Book next-day installation in most UK areas, subject to availability.
Use Gas Safe registered, insured and qualified engineers.
Get a manufacturer guarantee of up to 10 years on selected boilers.
Receive a separate 12-month Heatable workmanship warranty.
Pay by card or choose an eligible finance option.
Use Heatable’s price promise on qualifying like-for-like quotes.
Heatable was also a Which? Trusted Trader in 2023, 2024 and 2025 and has more than 10,000 five-star customer reviews.
Related reading:
How to get a new boiler 👻
You may need a new boiler.
You may need it fast and with affordable monthly payments.
You may even need it from a company with top-end local engineers, with 10,000 Trust Pilot reviews to back them up. Plus a Which? Trusted Trader award for good measure.
You may need a new boiler quote from us, Heatable 😘
