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Best Gas Boilers to Buy: Prices & Comparison

Becky Mckay
By: Becky Mckay
Updated: 4th February 2022

the best gas boiler

Boilers are without question, the heart of our homes. They keep us warm and provide us with a vital hot water supply. For around 85%1 of homes in the UK, our boilers are powered by natural gas, which makes the world of gas boilers a huge and often confusing place.

If you're looking for a new gas boiler or a replacement for an old boiler that keeps breaking down, but you just don't know where to start – we're here to help!

The 5 best gas boilers

To save you time and reduce the stress of finding the best gas boiler, we've done the leg work for you. By researching the biggest brands, taking an indepth look at their latest and greatest boilers, we've compared customer reviews, industry awards and stand-out technology to find the best 5 gas boilers on the market today.

For each boiler, we've also asked the important questions:

  • How energy efficient is it? (Can it save you money on bills)
  • Is it suitable for homes of different sizes?
  • Is it future proof? (Will it last the test of time and is there a long warranty to cover it)
  • What's the environmental impact? And is this model ready
    for future changes?

Each boiler in our list is available in different types and sizes to suit all homes, but if you would like more tips on buying a new gas boiler, check out our complete guide to finding the best new boiler deal.

A recent Boiler Guide survey uncovered the top 5 brands most commonly installed (and most-loved) by homeowners. We've used the results, in the graph shown below, to form our best gas boilers list, by researching the very best boilers these popular brands have to offer.

Most Popular Boiler Brands Survey

1. Worcester Bosch Greenstar 4000

Price Range: £990 – £1,200 (excl. installation)
Types Available: Combi, System
Home Sizes: Small – Large
Worcester Bosch Greenstar 4000 Gas Boiler

Ranked as the number 1 choice of boiler brand in the recent Boiler Guide survey2, Worcester Bosch has proven to be a popular, trusted manufacturer amongst home owners.

The Greenstar range is consistently rated highly for reliability and quality and the new 4000 model, released in 2021, was quickly awarded as a 'Which? Best Buy'2 – so you can see why it's earned a spot in our top 5.

Worcester Bosch have stated the Greenstar 4000 is their most environmentally friendly gas boiler to date, which is a big claim ...but here's why:

  • This boiler comes in a range of outputs, which means you can choose the most appropriate level of power for your home. This ensures you don't waste money burning more fuel in a boiler that's too big for your needs.
  • An exciting new feature, known as 'Quick Tap' lets you indicate to your boiler (with one quick flick of the hot tap, on then off) that you want hot water – then when you go back to the tap a second time, the hot water is instant3. This is a really interesting way of preventing water waste and also avoids that irritating wait for water to get hot on the chilliest of days.
  • Worcester Bosch has stated that their entire gas boiler range is capable of running on a 20% hydrogen blend. Hydrogen fuel is still in development, but this is a great step in future proofing this unit for a time when natural gas may be phased out as a fuel source. You can find out more about hydrogen gas in our guide to hydrogen energy.

Other plus points:

  • It's 'Quiet Mark' awarded – meaning it's one of the quietest gas boilers you can get
  • Wireless controls (with Bosch's 'EasyControl')
  • It's packaging is 99.9% recyclable
  • The system boiler is compatible with solar panels, for additional energy savings and reduced environmental impact
Types Available Combi System
Outputs 25kw, 30kw 12kw – 24kw
Efficiency Rating A-rated (CH, DHW) A-rated
Warranty Up to 10 years** Up to 10 years**
*CH: Central Heating, DHW: Domestic Hot Water
**When fitted by Worcester Accredited Installer

Find out more about Worcester Bosch Boilers

2. Vaillant ecoTec Plus

Potential Cost: £1,060 – £1,410 (excl. installation)
Types Available: Combi, System, Regular (Conventional/Open Vent)
Home Sizes: Small – Large
Vaillant ecoTEC plus gas boiler
Ranking second in our home heating survey, Vaillant is another highly popular choice amongst engineers and homeowners.

EcoTec Plus is the flagship model for Vaillant and they can boast some incredible tech inside these highly efficient boilers.

By learning when you don't use it as much, this gas boiler can drop to 16% of its power to save fuel – and your pennies, win-win!

Vaillant claims they always aim for low energy consumption, high performance and ease of use, which we can see in the following features:

  • A-rated for hot water and heating efficiency
  • Hot water within 5 seconds
  • Simple backlit display
  • Quiet Mark awarded

Vaillant are currently testing all of their boilers to confirm compatibility with a 20% hydrogen blend. This is a good indication that these boilers may soon be secure for any possible gas supply changes.

Types Available Combi System Regular (Conventional)
Outputs 25kw – 38kw 12kw – 37kw 12kw – 35kw
Efficiency Rating A-rated (CH, DHW) A-rated A-rated
Warranty 5 – 10 Years** 5 – 10 Years** 5 – 10 Years**
*CH: Central Heating, DHW: Domestic Hot Water
**Warranty may extend up to 10 years if a Vaillant Advance installer is used

Discover more about Vaillant Boilers

3. Ideal Vogue Max

Potential Cost: £1,200 – £1,400 (excl. installation)
Types Available: Combi, System
Home Sizes: Small – Large
Ideal Vogue Max Gas Boiler
Part of Ideal's premium range, the Vogue Max is made to be long lasting, stylish and reliable.

This gas boiler has a number of features similar to its companions in this list, but it does offer a few extras that make it stand out.

Ideal have designed their own magnetic system filter which comes with the boiler. This is a great tool that sits within your pipework and filters out all the impurities from your water. This can help to extend the life of the boiler, improve efficiency and reduce running costs. This filter also comes with a 10-year warranty, so it's a great bonus to the whole set-up.

Other noteworthy features:

  • Extensive 12-year warranty offer, including parts and labour
  • Lightweight design for quick and easy installation
  • Compact cupboard fit
  • Ready to run on 20% hydrogen blend
Types Available Combi System
Outputs 26kw – 40kw 15kw – 26kw
Efficiency Rating A-rated (CH, DHW) A-rated
Warranty 10 – 12 years** 10 – 12 years**
*CH: Central Heating, DHW: Domestic Hot Water
**12 year when installed and serviced by a Max accredited installer (other terms may apply)

Learn more about Ideal Boilers

4. Baxi 800

Potential Cost: £900 – £1,200 (excl. installation)
Types Available: Combi, System, Regular (Conventional)
Home Sizes: Small – Large
Baxi 800 Gas Boiler
Released in 2019, the Baxi 800 range was released with the aim of providing an efficient and reliable gas boiler that would last.

This boiler also includes a magnetic filter, so users can feel confident their pipework is protected and maintenance issues will be kept at bay.
With the range available in combi, system and regular versions, all sizes of home can benefit from what this boiler has to offer.


  • 10-year warranty which includes parts and labour
  • Adey Micro2 magnetic system filter to protect the heating system and boiler
  • Compact design allows for installation within a kitchen cupboard
  • 20% Hydrogen ready
Types Available Combi System Regular (Conventional)
Outputs 25kw – 36kw 12kw – 37kw 12kw – 35kw
Efficiency Rating A-rated (CH, DHW) A-rated A-rated
Warranty 10 years** 10 years** 10 years**
*CH: Central Heating, DHW: Domestic Hot Water
**Terms apply

Read more about Baxi Boilers

5. Viessmann Vitodens 200-W

Potential Cost: £1,190 – £1,550 (excl. installation)
Types Available: Combi, SystemViessmann Vitodens Gas Boiler
Home Sizes: Small – Large

Viessmann is another manufacturer with a great reputation. They are only the second brand of gas boiler to be given a 'Which? Best Buy'2 for 2021.

They rate highly for reliability and customer satisfaction and the 200-W model is perhaps the smartest gas boiler on our list.

This intelligent boiler has wifi capability which allows users to control everything via an app, making it highly convenient.

Viessmann can also boast that this model has a 98% efficiency capability – that's incredibly high! Making it one of the most energy-efficient gas boilers you can get. Great for the environment and your savings.

Other features:

  • Viessmann's 'MatriX' cylinder burner improves energy efficiency, keeps the boiler healthier for longer and reduces environmental impact
  • Colour touchscreen
  • Quiet operation
  • 12-year warranty available
  • Hydrogen ready
Types Available Combi System
Outputs 25kw – 32kw 11kw – 32kw
Efficiency Rating A-rated (CH, DHW) A-rated
Warranty 10 – 12 years** 10 – 12 years**
*CH: Central Heating, DHW: Domestic Hot Water
**Terms apply

More about Viessmann Boilers

Get the best gas boiler price

We hope these 5 fab boilers have given you some insight into what is available in the world of gas boilers, and what features are important to you. The next step you need to consider is how to get your new boiler at the best possible price.

Whilst boiler pricing can be straightforward, the cost of the installation can differ depending on a number of factors (How straightforward a replacement will be, if the boiler is to move position, if new pipework is needed etc.). That's why we always recommend comparing at least 3 quotes from qualified heating engineers. This gives you an idea of which quotes are more affordable and ensures you'll get the very best deal on the installation of your new boiler.

Here at Boiler Guide we find the engineers, so you don't have to. Simply fill in our quick online form and we will find up to 3 qualified installers in your local area who can provide you with free, no-obligation quotes. You can then compare high quality installers and have peace of mind that you're finding the best deal available.


1. Committee on Climate Change, Next Steps for UK Heat Policy; Annex 2 (2016)
2. Which?, Best Buy Boilers (2022)
3. When used in 'Eco Mode'. Worcester, Greenstar 4000: User Instructions. pg.19 (2020)

Becky Mckay

About the author

Becky Mckay

Becky is one of our home heating and renewable energy experts and has a wealth of experience writing about the world of heating.

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