Looking for a new gas boiler and trying to decide which installation company offers the best price, service and reliability?

With so many “boiler deals” advertised online and every company promising fast installs, long warranties and top-rated service, it can be difficult to know who to trust. This guide compares the UK’s leading boiler installers to help you make a confident, informed choice.

We’ve assessed warranty lengths, pricing, installation quality, fixed-price guarantees, finance options and overall value for money.

You could save up to £830 per year by replacing an old G-rated boiler with a new A-rated condensing boiler.*

This guide covers the most popular boiler installers in the UK, including Heatable, BOXT, WarmZilla, Boiler Central and British Gas.

Energy Guide Approved New Boiler Installers

Each company below has been reviewed using our independent 10-point criteria covering warranties, aftercare, pricing transparency, engineer qualifications and customer satisfaction.

Heatable

• Warranty: Up to 12 years
• Installation included: Yes
• Finance options: 0% APR available
• Fixed pricing: Yes

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BOXT

• Warranty: Up to 10 years
• Installation included: Yes
• Finance options: 0% APR available
• Fixed pricing: Yes

View quote

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British Gas

• Warranty: 5 years
• Installation included: Yes
• Finance options: 0% APR available
• Fixed pricing: Yes

View quote

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Boiler Central

• Warranty: Up to 12 years
• Installation included: Yes
• Finance options: 0% APR available
• Fixed pricing: Yes

View quote

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WarmZilla

• Warranty: Up to 12 years
• Installation included: Yes
• Finance options: 0% APR available
• Fixed pricing: Yes

View quote

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Best Boiler Installers/Companies Compared

When comparing boiler installation companies, there are several important factors to consider beyond just the headline price. A boiler is a long-term investment, so choosing the right installer helps ensure reliability, long-lasting performance and secure warranty protection.

Below are the main things to look out for when comparing boiler fitters in the UK:

• Do they offer fixed-price quotes? Ensures the price doesn’t increase on installation day.
• What warranty length is included? Longer warranties offer better long-term protection.
• Do they offer boiler cover or servicing plans?
• Do they provide a workmanship warranty?
• Are their engineers Gas Safe registered?
• What is their customer service reputation?
• Do they offer next-day installation?
• Which boiler brands do they supply?
• Are their boilers hydrogen-ready?
• Do they offer additional services? Such as radiators or hot water cylinder installations.

These questions form the basis of how we assess the major boiler installers. Although many appear similar, differences in warranty length, the boiler brands supplied, and aftercare can significantly affect overall value.

Below, we break down individual comparison points to help you make the right decision.

Which boiler installers offer a fixed price?

A fixed-price quote is one of the most important features to look for when choosing a boiler installation company. With a fixed price, what you’re quoted online is exactly what you’ll pay—no unexpected increases on the day.

A fixed-price boiler quote ensures there are no hidden costs or last-minute surprises during installation.

Most major online boiler installers now offer fixed-priced quotes, including Heatable, BOXT, Boiler Central, WarmZilla and British Gas. This gives homeowners more confidence and ensures transparency around costs.

Just make sure you upload accurate photos and provide the correct details during your online quote to ensure the price is confirmed correctly.

To compare the boilers these companies offer, visit our guide to the best boiler brands.

You can also read our detailed installer reviews here:

• Boiler Central Review
• WarmZilla Review
• BOXT Review
• British Gas Boiler Review
• iHeat Review
• E.ON Boiler Review
• Heatable Review

New Boilers with the Best Warranty Periods

A strong boiler warranty provides protection from costly repairs. Warranty length varies by brand and installer, with most offering between 5 and 12 years of cover.

To keep your warranty valid, you must:

• Have the boiler serviced every year
• Register the boiler within 30 days of installation
• Use a Gas Safe engineer for all work

Most leading installers offer models with at least a 10-year warranty, and some offer up to 12 years of total cover.

Some of the longest warranty periods include extended cover supplied by the installer rather than the boiler manufacturer. While this still offers full protection, some homeowners prefer warranties backed directly by the boiler brand.

Do all boiler installers offer boiler cover?

Not every boiler installation company offers boiler cover, but this isn’t usually an issue since you can take out a separate service plan from a third-party provider if needed.

Some companies, such as British Gas, BOXT and Boiler Central, offer both installation services and optional monthly boiler cover plans.

Whether boiler cover is worth it depends on your situation. Consumer organisations like Which? often suggest that paying for repairs as they occur can be cheaper than long-term cover plans.

Do the best boiler installers offer a workmanship warranty?

Most reputable online installers provide a workmanship warranty of at least 12 months. This protects you from issues caused by installation mistakes, such as leaks or incorrect fittings.

A workmanship warranty means the installer will fix installation-related problems free of charge during the first year.

This gives homeowners peace of mind, especially when using an installer that completes thousands of jobs each year and relies heavily on customer reviews.

Are the boiler installers qualified?

All installers listed in this guide employ Gas Safe registered engineers. This is a legal requirement for anyone installing or repairing gas boilers in the UK.

On installation day, you can ask to see the engineer’s Gas Safe ID card. You should check:

• The engineer’s photograph
• The expiry date
• The 7-digit licence number
• The security hologram
• The appliances they are qualified to work on (ensure it includes gas boilers)

If you want to explore alternative boiler designs, see our guide to floor-standing boilers.

You can also read our reviews of the boiler brands to avoid and the most reliable boilers.

Learn more about the different types of boilers, including LPG, oil and condensing boilers.

Customer reviews and reputation

Customer reviews provide one of the clearest indicators of installer quality. While review scores vary between platforms, most large online installers have strong reputations for reliability and customer service.

Newer companies often score highly due to streamlined processes and quicker installation times. Traditional providers can have mixed reviews due to a broader range of services and longer waiting times.

For help with common heating issues, see our guides on boiler lockouts, ignition faults, PCB faults, and timer problems.

Do installers offer next-day boiler installation?

Many companies advertise next-day installation, but availability can vary based on location and demand—especially during winter.

Where possible, booking your installation in advance gives you more flexibility.

If you’re unsure which boiler size you need, see our guide to the best combi boilers and the boiler size calculator.

For a full overview, visit our boiler installation guide.

Do they offer radiators and hot water cylinders?

If you need more than just a boiler—such as new radiators or a replacement hot water cylinder—the choice of installer matters.

BOXT and British Gas offer complete central heating packages, including radiators and unvented cylinders. Some online-only boiler providers focus exclusively on boiler swaps.

How much is a new boiler installation in the UK?

The cost of a new boiler varies depending on your home, boiler brand, warranty length and installation requirements. Prices also differ based on location and whether additional work is needed.

Factors that influence the price include:

• The type of boiler (combi, system or heat-only)
• The brand and warranty length
• Whether the boiler is staying in the same location
• Any extra pipework or radiators required
• Whether scaffolding or flue changes are needed
• Emergency call-outs during peak times

To estimate your cost, use our boiler installation calculator.

New Boiler Installation FAQ

Below are some of the most common questions homeowners ask when considering a new boiler installation.

How much can you save with a new boiler?

The savings depend on the age and efficiency of your current boiler. Replacing an old G-rated model with a modern A-rated condensing boiler can reduce annual fuel bills by as much as £340, depending on your home size and heating usage.

Average Cost of a New Boiler in the UK

It’s difficult to give a single “average” price due to the number of variables involved. However, a typical like-for-like combi boiler installation usually costs between £1,500 and £2,000.

For more detailed pricing, see our cost breakdown guides:

• British Gas new boiler costs
• How much is it to fit a new boiler?
• Vaillant boiler prices
• Baxi boiler costs

How long does a new boiler take to install?

Most boiler replacements are completed within a single day, particularly if you are replacing a combi boiler with another combi in the same location.

Boiler conversions (e.g., system boiler to combi) or relocations may take longer—typically 1.5 to 2 days depending on the complexity of the work.

Are there government grants for new boilers?

There are currently two main government schemes relating to home heating in the UK:

• ECO Scheme (Energy Company Obligation): Offers free or discounted boiler upgrades to households that meet income and eligibility criteria.
• Boiler Upgrade Scheme (BUS): Offers £5,000 towards biomass boilers or heat pumps, but cannot be used for new gas boilers.

Who offers the best new combi boiler deals?

The best deal depends on what you value most—whether that’s the warranty, the brand of boiler, the total installation cost or the speed of installation.

It’s always recommended to compare multiple quotes and ensure each company is providing a like-for-like boiler and installation setup.

If cost is your main concern, see our guides to affording a new boiler and boilers on finance.

New Boiler Scheme – What Is It?

The Boiler Upgrade Scheme (BUS) provides a £5,000 grant towards qualifying renewable heating systems such as biomass boilers and heat pumps. It is not applicable to gas boilers.

New Back Boilers – Are They Still Available?

Back boilers are no longer installed in the UK. They were discontinued due to safety and efficiency regulations. If you currently have one, it can be decommissioned and replaced with a modern combi or system boiler.

For deals and comparisons, visit our guides to the best boiler deals and the top online boiler installers.

Is It Worth Getting a New Boiler Now? (Considering Potential Bans)

There is currently no plan to ban gas boilers in existing homes. The only confirmed policy is a ban on gas boilers in new-build homes from 2025 onwards.

If you have a very old non-condensing boiler, replacing it now can reduce both your energy bills and your carbon footprint.

*Savings estimate based on replacing an older G-rated boiler with an A-rated condensing boiler, as outlined by the Energy Saving Trust.