A Gas Safe engineer installing a new condensing combi boiler in a UK home
Independent UK new boiler guidance

Straight answers about new boilers.

No sales pitch, no scare tactics — just clear, accurate guidance on boiler types, realistic costs, what to expect during installation, available grants, and how to choose a Gas Safe registered engineer. Sourced from the Gas Safe Register, Energy Saving Trust and Building Regulations.

Free · no obligationSourced from Gas Safe Register & Energy Saving Trust
Gas Safe Register & Energy Saving Trust sourced Independent guide, not an installer Free, no-obligation quote enquiry

In 40 seconds

Most UK homes need a 24–35 kW condensing combi boiler, which costs £1,500–£3,500 supply and fit in 2026. The right size depends on your number of radiators and bathrooms; the right type — combi, system or regular — depends on your home’s hot-water demand. All gas boiler work must be carried out by a Gas Safe registered engineer. If you are on a qualifying benefit, the ECO4 scheme may fund part or all of the cost; the Boiler Upgrade Scheme offers £7,500 toward a heat pump instead. Get at least three itemised quotes, check Gas Safe registration at gassaferegister.co.uk, and always receive a Benchmark Commissioning Checklist and Gas Safe certificate on completion.

£1.5k–3.5k
typical combi supply-and-fit cost
10 years
maximum warranty (Worcester Bosch / Vaillant accredited)
£7,500
Boiler Upgrade Scheme grant toward a heat pump
0
obligation — comparing quotes is free
The answer library

Every question people actually ask about getting a new boiler.

Organised the way you think about it — what type and size you need, what it costs and why, what the installation involves, what grants are available, and how to choose the right brand and installer.

Boiler basics

What kind of boiler you need, how it works and how to size it — the foundations before any quote or installation decision.

Basics

What size boiler do I need?

Output in kilowatts, number of radiators and bathrooms — how to match the boiler to your home.

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Basics

Combi vs system vs regular boiler: which type do you need?

The three types of gas boiler explained — and how to match them to your home’s hot-water and heating needs.

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Basics

How does a combi boiler work?

One unit, two jobs — central heating and instant hot water explained step by step.

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Basics

What is a system boiler?

A sealed-system boiler with a hot-water cylinder — who it suits and how it works.

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Cost & pricing

Realistic 2026 supply-and-fit prices for every boiler type — line by line, so you can compare quotes fairly.

Pillar guide

How much does a new boiler cost in the UK?

Typical 2026 supply-and-fit prices for combi, system and regular boilers — and what drives the difference.

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Cost

How much does a combi boiler replacement cost?

Supply-and-fit prices by brand tier and boiler size — and what the quote should include.

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Cost

How much does it cost to convert to a combi boiler?

Removing cylinders and loft tanks, re-routing pipework — what conversion adds to a standard replacement.

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Cost

Boiler installation cost breakdown: what is in the price?

Line by line — what every element of a boiler installation quote typically costs and why.

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Process & install

From the first flush to the final Benchmark certificate — what a proper boiler installation involves and how long it takes.

Install

How long does a boiler installation take?

A standard combi swap is usually one day — here is what takes longer and why.

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Install

Do I need a power flush before a new boiler?

Sludge, cold spots and magnetite — when a power flush is genuinely needed and when it is not.

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Install

How much does it cost to move a boiler, and what are the rules?

Gas pipe routes, flue positions and Building Regulations — what governs where a boiler can go.

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Install

Boiler installation: what should I expect on the day?

Step by step from the engineer arriving to your new boiler firing up — what a proper installation looks like.

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Grants & reassurance

ECO4, the Boiler Upgrade Scheme and when to replace — what help is available and how to decide with confidence.

Grants

What grants are available for a new boiler in the UK?

ECO4, the Boiler Upgrade Scheme and other help — eligibility, amounts and how to apply.

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Grants

The Boiler Upgrade Scheme explained: how does the heat pump grant work?

What the BUS grant covers, who qualifies, and what a heat pump actually costs after the grant.

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Grants

What are the signs that I need a new boiler?

Age, repair cost, efficiency and safety — the indicators that replacement makes more sense than repair.

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Grants

What boiler warranty should I get?

Two years to ten years — what cover means in practice and whether it is worth paying for.

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Comparison & choosing

Brands, fuel types, installers and quotes — how to choose well once you know what you need.

Compare

Which combi boiler brands are most reliable in the UK?

Worcester Bosch, Vaillant, Ideal, Baxi and others — what the reliability data and warranty terms say.

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Compare

Worcester Bosch vs Vaillant vs Ideal: which boiler should you choose?

A direct comparison of the UK’s three most popular boiler brands on price, warranty, reliability and installer access.

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Compare

Oil vs gas vs LPG boiler: which fuel type is right for your home?

Mains gas, heating oil and LPG — availability, running costs and what changes at installation.

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Compare

How do I choose a boiler installer in the UK?

Gas Safe registration, accreditations, quotes and red flags — a practical checklist.

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Compare

How do I get new boiler quotes — and how should I compare them?

What to tell engineers, what a good quote looks like, and how to compare fairly.

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How it works

From first question to new boiler firing, in three steps.

You don’t need to have decided on a boiler before you enquire. A Gas Safe registered engineer will assess your home, recommend the right type and size, and give you a fully itemised quote.

  1. Tell us about your home. A short, no-obligation enquiry — your home size, current boiler type and what you’re looking for. The more detail you give, the more accurate the quotes.
  2. Get quotes from Gas Safe engineers. We connect you with Gas Safe registered engineers in your area who will carry out a site visit and give you a fully itemised supply-and-fit quote.
  3. Compare and choose with confidence. Review the quotes side by side — boiler model, warranty, scope and price — and choose the engineer you trust. No pressure, no obligation.

Ready to compare boiler quotes?

Getting at least three quotes from Gas Safe registered engineers is the single best thing you can do to ensure a fair price and a properly specified installation. It’s free to enquire and there’s no obligation to proceed.

Free to use. No obligation. We are an independent guide, not an installer.