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Last updated: 2nd January, 2024


Best Eco Friendly Boilers for 2024

Best Eco Friendly Boilers for 2024

The UK Government has set out its net-zero carbon emissions by 2050 target and have started encouraging people to start making more eco-friendly purchases in preparation.

As more of us become aware of our impact on the environment and the effect inefficient appliances have on our energy bills, finding products and services that produce no or fewer emissions is becoming a higher priority for many.

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In this guide, we’ll be taking a look at some of the most eco-friendly & energy efficient boilers available on the market. 

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Biomass Boilers

Biomass boilers burn natural materials such as wood pellets, chips and logs to provide heating and power hot water boilers.

Put simply, biomass is any organic material that can be used as fuel, though wood pellets tend to be the most commonly used for boilers in the UK market.

The downsides to biomass boilers are the initial cost and practicality of running. Manually feeding the wood pellets can be impractical and time consuming, something which many homeowners won’t want the hassle of doing

It’s also worth noting that although biomass boilers are more eco-friendly than gas boilers, they still contribute to pollution to some extent.

How Much Do Biomass Boilers Cost?

Generally, biomass boilers range from £5,000 to £10,000

This is of course a much bigger purchase price compared to a standard combi boiler, which you can get for around £1,200-£2,800 including installation.

However, you may qualify for the Domestic Renewable Heat Incentive which will help to make it more affordable.

The Most Eco-Friendly Biomass Boilers

Grant Spira 36kW

One of the best eco-friendly biomass boilers on the market today is the Grant Spira 36kW

Featuring Grant’s patented stainless steel turbulator baffle system, the Spira Condensing Wood Pellet Boiler delivers award winning efficiency of up to 93.1%, with outputs ranging from 5kW to 72kW.

SEAI awarded the Spira "The best renewable energy product" in 2011 on its launch due to its unique twin baffle system. 

Grant Spira 36kW

Windhager FireWIN Klassik 12kW

Another highly efficient biomass boiler is the Windhager FireWIN Klassik which starts from £9,025 and is 94% efficient.

The FireWIN Klassik is a state of the art wood pellet boiler combined with the features of a room heating stove available in outputs from 3.8-12kW.

Its stylish finish along with a host of innovative Windhager features makes it ideal for any low carbon home, delivering efficient heating whilst still looking great in either red, grey or cream.

Windhager FireWIN Klassik 12kW

Electric Boilers

Electric boilers tend to be much cleaner than biomass boilers, especially if you use renewable energy sources to power them, such as solar or wind power. 

These boilers function in a similar way to combi gas boilers but use electricity to generate heat instead of burning fossil fuels. 

How Much Do Electric Boilers Cost?

Electric boilers are still a lot more expensive to purchase initially compared to gas boilers, however, they’re a lot more affordable to run, saving you money in the long run.

An electric boiler will typically set you back anywhere between £1,000-£2,000- and that's without the addition of installation costs.

The Most Eco-Friendly Boiler Models

Elnur Mattira MAC15

The Mattira MAC15 from Elnur is 100% efficient. Yes, you heard us right. 

This incredibly efficient boiler is available in a wide range of outputs from 3kW to 15kW, making it the perfect electric boiler model for any home. 

Available Power Outputs:

3kW / 4kW / 5kW / 6kW / 7kW / 8kW / 9kW / 10kW / 11kW / 12kW / 13kW / 14kW / 15kW

Elnur Mattira MAC15

Electric Heating Company Comet Combi Boiler

The Comet Combi Boiler from Electric Heating Company is another electric boiler that is 100% efficient.

This combi is available in outputs of 9kW, 12kW and 14.4 kW, making it another model that is ideal for homes of all sizes.

Electric Heating

Combi Boilers

Although combi boilers still use fossil fuels such as gas and oil, some manufacturers have developed incredibly efficient models in order to minimise emissions and make them as eco-friendly as possible. 

How Much Do Combi Boilers Cost?

A combi boiler is one of the most affordable boiler types available, both to purchase and install, as they do not require an additional water tank and hot water cylinder which involves extra labour costs.

You can typically purchase a combi boiler plus installation for between £1,200-£2,800 depending on the brand, size (in kW), model and features.

Which Combi Boiler Should I Choose?

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The Most Eco-Friendly Combi Boilers

Ideal Logic + Combi

The Ideal Logic + Combi 24kW has 28mg per kWh of Nitrogen Oxide emitted, giving it an ERP rating of 89%. 

Thanks to its A-rated 89% energy efficiency, you can make incredible savings on your heating bills whilst reducing your carbon footprint, all without changing your consumption.

The Logic+ is part of Ideal’s ErP range which means it has been designed with energy efficiency in mind.

You can get a brand new Ideal Logic + Combi boiler plus installation for as little as £1,895 with iHeat. Get a quote today.

Ideal Logi+ Combi

Viessmann Vitodens 050-W Combi

The Viessmann Vitodens 050-W 25kW Combi has an ERP rating of 92%, making it one of the most efficient gas combi boilers on the market.

This boiler has the potential to significantly cut fuel costs whilst being incredibly reliable and offering a new high quality stainless steel heat exchanger, making it extra robust whilst consuming relatively little natural gas.

Viessmann Vitodens 050-W

Conventional Boilers

For large homes with multiple bathrooms, conventional boilers are more suitable than combi units as they can meet a higher demand. 

However, as they also use gas they are significantly less efficient than electric boilers and because they must store hot water for long periods of time as opposed to heating the water on demand, they’re also a lot less efficient than combi boilers. 

Despite this, many manufacturers offer ErP A rated conventional boilers, meaning they are over 90% efficient.

How Much Do Conventional Boilers Cost?

The cost of a new conventional boiler can range anywhere between £800 to £1,500 for just the unit alone.

If you start adding on installation costs, a new cylinder and new water tanks, you could be looking at paying around £2,500.

This is of course a lot more expensive than a combi boiler, which acts as a single unit without the need for a hot water cylinder or water tank.

The Most Eco-Friendly Conventional Boilers

Alpha E-Tec 25R 25kW

Our top pick for the most eco-friendly heat only boiler is the Alpha E-Tec 25R 25kW, which has an incredible fuel efficiency rating of 93%!

The E-Tec range features a brand new stainless steel heat exchanger and is Alpha’s most compact unit yet. 

Being compact allows an easy fit in a standard kitchen cupboard and servicing is made easy with front access.

It even comes with a huge 10 year warranty when installed by iHeat!

Worcester Bosch Greenstar Ri 18kW

A close second in our top picks for the most eco-friendly conventional boilers is the Worcester Bosch Greenstar Ri 18kW, which has a fuel efficiency rating of 92%!

The Greenstar Ri boiler is a compact, wall mounted boiler that is ideal for small to medium sized homes, available in a range of outputs from 9kW to 24kW. 

Eco-Friendly Boilers at iHeat

At iHeat, we offer a wide range of A-rated efficient combi, system and conventional boilers to keep your home warm whilst keeping the heating bills down and minimising your impact on the environment. 

Get a free fixed quote on a brand new boiler plus installation today at iHeat.

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Stephen Day profile photo
Article by
Stephen Day | Co-founder
Gas Safe registered and FGAS certified engineer with over 20 years experience in the heating and cooling industry.