Save up to £590 PER YEAR on your heating billsGet Your FREE Online Quote Today
Save up to £590 PER YEAR a yearNeed a New Boiler?
Witten by Bernard Morgan (Engineer) & Adam Apperley (Marketing). Published: June 16, 2022. Updated: January 26, 2024

Hydrogen Boiler explained

An introduction to hydrogen boilers

If they reach the market, hydrogen boilers can burn 100% hydrogen gas. As a clean-burning fuel, a hydrogen boiler would be a clean alternative to natural gas.

Unfortunately, there are no plans to transition the gas network to 100% hydrogen anytime soon. It wouldn’t work at all without major changes to the network. For example, hydrogen is the smallest element in the universe, and the network would leak…a lot.

Instead, the current plan is to mix hydrogen with natural gas to reduce our reliance on the fossil fuel.

How are hydrogen blend or Hydrogen-ready boilers different?

old boiler to combi replacement

20% Hydrogen blend/ready boilers are the first step to securing the zero-carbon alternative to heating homes. Manufacturers are focusing on introducing hydrogen-ready boilers rather than 100% hydrogen boilers. This aligns with the government’s plans to phase in the blended fuel rather than making an instant transition.

This blend is expected to be introduced in 2028. It will be 20% hydrogen and 80% natural gas. Predictions suggest this 20% reduction of natural gas will generate the same reduction in emissions as taking 2.5 million cars off the road.

What about hydrogen fuel cells?

Rather than combustion, hydrogen fuel cells convert hydrogen into electricity and heat. This is a chemical reaction. Water is the only waste product of the chemical process. These low-carbon alternative batteries produce clean energy for several applications.

Industries such as transportation are actively trying to introduce the use of hydrogen within cars and vehicles. The fuel source guarantees efficiency and zero emissions. Developments have also been made in domestic heating.

The Viessmann Vitovalor CHP generates up to 18 kWh of electricity per day using hydrogen fuel cells and is highly efficient at heating water. Despite its many benefits, the cost of replacing boilers nationwide with this type of system would be far too expensive.

Why is there a need for an alternative fuel source?

boiler icon

Since the introduction of gas boilers in 1868, fossil fuels, including natural gas, have been used to heat water for taps and central heating. This continual combustion of natural gas to heat our homes contributes to 19% of global greenhouse gas emissions. Within the UK alone, central heating produces one-third of carbon emissions.

Not only are fossil fuels non-renewable and running out, but the release of carbon dioxide into the atmosphere is damaging the planet. Greenhouse gases cannot escape the earth’s atmosphere and trap heat from the sun. This causes a temperature rise, changing the earth’s climate.

Overwhelming attention has finally been directed toward the global climate crisis. The UK, along with many countries across the globe, have pledged to reduce carbon emissions and limit their impact on climate change.

Why Hydrogen?

Low-carbon alternatives to natural gas have been suggested. Installing solar thermal panels or a heat pump provides carbon-free heat and electricity. But, replacing gas boilers in every home would be impractical, time-consuming and expensive.

Rather than replacing the heating system, the focus has been placed on alternative fuel sources. Hydrogen gas, when produced cleanly, is a highly efficient energy carrier that only generates water as a waste product. It is even more fuel-efficient than natural gas as an energy source. 1kg of hydrogen releases the same energy as 2.8kg of natural gas. For lowering carbon emissions, burning hydrogen instead of natural gas appears to be an ideal solution.

Why can’t we use 100% hydrogen boilers sooner?

Hydrogen is one of the planet’s most abundant resources, and there are plenty of methods of producing more. However, due to the delay in logistics and infrastructure, the technology needed to supply hydrogen gas to homes across the country is years from being fully integrated. 

One of the core factors preventing the replacement of current gas boilers is that to produce hydrogen, a method of mass production that isn’t carbon-intensive needs to be developed.

Steam methane reforming (SMR) is the procedure that is currently used to generate most of the hydrogen fuel consumed within the UK. It is significantly carbon-intensive and relies on unsustainable fuel sources. Due to the limitations of this procedure, the replacement of current gas boilers has halted.

The SMR process harnesses the products of a reaction between natural gas, steam and a catalyst. Unfortunately, hydrogen is not the only product of the reaction; carbon monoxide is also produced. Unsustainable amounts of natural gas are required for the reaction, increasing rather than reducing carbon emissions. 

Predictions have suggested that the technology to produce clean hydrogen gas won’t be available for another ten years. However, this hasn’t prevented the government from continuing to trial hydrogen and pursuing the boiler upgrade scheme. At the current rate, the goal is to introduce a hydrogen and natural gas blend into the mains supply by 2025. This will mark the beginning of the transition to a much cleaner energy source.

Get Your FREE Online Quote Today!
Save up to £590 PER YEAR on your heating bills.
Quote in 30 seconds. No obligation. Next Day installation.
Save up to £590 PER YEAR!

How hydrogen ready boilers work

Hydrogen gas and natural gas create slightly different reactions when combusted. However, this won’t require significant changes to the components of hydrogen ready boilers. The addition of certain features will accommodate the requirements of burning hydrogen, but the overall process of generating heat remains the same. 

Once hydrogen gas is introduced, the blended fuel will be supplied using the existing gas network. This gas will enter the boiler and combine with oxygen before heating to combustion via a catalytic burner. As a result of this combustion, hot flue gases will enter the heat exchanger. This includes a series of pipes surrounded by cold water. As the hot gases travel through the pipes, the surrounding water is heated to be sent to the tap or travelled around the central heating system. Hot flue gases exit via a flue with small amounts of NOx emissions generated during combustion.

Accounting for a much lighter and flammable gas, hydrogen ready boilers need to be fitted with specific burners, which limit the flames should too much gas enter the system. Additionally, hydrogen produces invisible flames when burnt. Therefore, flame detection components will be implemented within the hydrogen boiler.

When transitioning from natural gas to hydrogen blend fuel, gas registered engineers, plumbers and boiler installers will complete the relevant training to become acquainted with the components of new hydrogen boilers. Boilerhut installers will efficiently complete hydrogen blend and hydrogen boiler installations. Our team is always equipped with up-to-date training and expertise.


  • Cleaner energy
    Burning fossil fuels to generate heat creates massive amounts of carbon as a waste product. This carbon is released into the atmosphere, causing detrimental effects on our climate. When produced cleanly, hydrogen’s waste products include water and minimal amounts of nitrous oxide. The switch to this fuel would have subsequent positive effects on the current climate crisis. In the coming years, just switching 20% of our current gas supply to hydrogen will present monumental reductions in carbon emissions.
  • No need to overhaul existing infrastructure
    Fortunately, the existing pipelines and infrastructure used to transport and supply natural gas can be repurposed. Instead of rebuilding the entire system, some modifications to the existing infrastructure will save significant expenditure and prevent additional carbon emissions that may have been produced during the construction process.
  • Cheaper bills
    Hydrogen is a far more efficient fuel than the natural gas currently used within boilers. As an efficient energy carrier, it will take significantly less fuel to produce enough heat for one house. Due to the reduction in fuel consumption, domestic bills should drastically decrease. The unsustainability of natural gas is one of the key factors that constantly drives energy prices. As seen with the current gas supply, the inability to procure resources increases prices exponentially. With established production and transportation routes, efficiently produced hydrogen fuel sources would significantly decrease domestic prices.


  • Extremely flammable
    The hydrogen element consists of just two hydrogen atoms attached via one proton and one electron. This simple chemical structure makes it light in mass, odourless, non-toxic and extremely flammable. Compared to natural gas, the use of hydrogen does pose a higher risk when ignited. Boiler manufacturers will therefore implement safety mechanisms to reduce the risk. Excess flow valves are one of these mechanisms. It controls the release of gas into hydrogen boilers to prevent excess amounts from causing ignition risks.
  • Difficult to store and transport
    Cost and practicality are two of the main concerns associated with the transportation and storage of hydrogen gas for domestic use. To be condensed into a liquid form for transportation and storage, 1.01 of pressure and a temperature of -257.87℃ need to be achieved. Compared to natural gas liquefaction, a reduced pressure of 0.25 bar and temperature of just -162℃ is required. Liquefication of hydrogen consumes up to 30% of it’s energy content, and the process is expensive. Research into improved technology for hydrogen liquefaction is required to provide a more efficient and cost-effective process.
  • Expensive to produce
    There are two standard methods of producing hydrogen used for the mass market. These include SMR and electrolysis. Currently, these processes are either unsustainable or ill-suited to provide the quantity of hydrogen needed for the purpose of heating water within homes. SMR is the process of combining steam and natural gas with a catalyst. This is currently the most widely used process for the production of hydrogen. Electrolysis is a carbon-free alternative that uses electricity to split water into hydrogen and oxygen. Currently, this procedure is only suited for small scale production rather than meeting the demands of the entire country.

When will hydrogen boilers be available in the UK?

There are several challenges concerning production, transportation, and hydrogen utilisation to overcome before the switch occurs. As it stands, 100% hydrogen ready boilers are not yet available on the UK market. 

However, significant progress has been made by manufacturers Worcester Bosch, Viessman and BAXI. Hydrogen blend ready boilers are now available for purchase and installation today. 

Due to the logistics and development associated with the integration of hydrogen into our energy supply, the UK government has laid out a timeline for particular milestones to be achieved. 

Phase 1: By 2025, all boilers should be built and available at a hydrogen-ready standard. Whilst they will be capable of operating using natural gas initially, modifications will allow these heating systems to transition to 100% hydrogen fuel. 

Phase 2: 20% hydrogen blend will be introduced into the energy supply. This adjustment is not expected until 2028, providing homes with gas boilers the opportunity to acquire a hydrogen boiler. 

Phase 3: Eventually, the gas network throughout the UK will be transitioned to 100% hydrogen fuel. Due to the significant developments that need to be made before this change, the switch is not expected to happen before 2040. 

How much will a hydrogen boiler cost?

Whilst there aren’t currently any commercial models of hydrogen boilers available, a price promise made by four boiler manufacturers has provided an idea of the expected cost. Worcester Bosch, Vaillant, Baxi, and Ideal have formed a joint initiative concerning the development of hydrogen ready boilers. 

The initiative has confirmed that new hydrogen boilers will not cost more than the natural gas equivalent. This is expected to save consumers billions of pounds and demonstrates the manufacturer’s dedication to the zero-carbon solution.

Combi and system gas boilers typically cost between £600-900 for a budget model, £900-1200 for mid-range spec, and £1000-2000 for a premium boiler. Whilst these prices are likely to fluctuate and change, the cost of a new hydrogen boiler won’t significantly exceed these price brackets. 

Installation is another cost that needs to be considered when purchasing a hydrogen boiler. Due to the similarity in ancillary components, accessories and controls, the installation process won’t be dissimilar to natural gas boilers. Regulatory change mandating will require gas registered engineers to be fully trained in their installation, and hydrogen boilers will quickly become a high volume technology. This will reduce the cost to no more than installations for typical gas boilers. 

Get Your FREE Online Quote Today!
Save up to £590 PER YEAR on your heating bills.
Quote in 30 seconds. No obligation. Next Day installation.
Save up to £590 PER YEAR!

Looking for great deals on hydrogen boilers?

Boilerhut have stocked the highest quality hydrogen blend-ready boilers ready for the switch to hydrogen. Our boilers operate efficiently on natural gas with seamless transitions to hydrogen blends.

Here are just a few reasons you should purchase and install your new hydrogen-ready boiler from BoilerHut.

  • Hundreds of satisfied customers have rated us 4.9 on Trustpilot.
  • Save up to £590 per year with a new 20% hydrogen-ready energy-efficient boiler.
  • Gas safe registered installation across the UK.
  • Bespoke fixed-price online boiler quotes.
  • Spread the cost with alternative payment plans.
  • Warranties with all of our boiler models.

Best Hydrogen Ready boiler for 2024

Suppose you’re looking to get ahead of the change and invest in hydrogen early. In that case, it is essential to know which boilers offer the highest efficiency and durability once the transition to H2 blend fuel has been made. 

At BoilerHut, our current favourite hydrogen-ready boiler is:

Viessmann Vitdoens 100-w combi boiler

Viessmann’s A-rated powerful combi boiler is equipped with the latest water and central heating technology. Its user operating system is intuitively simple to control and offers unmatched convenience with the ViCare app

Amongst these accommodating features, you can also benefit from the following components:

  • MatriX-Plus burner – This burner creates the lowest noise and pollution emissions on the market whilst maintaining the ability to heat a home with up to 20 radiators.
  • Lambda Pro Combustion System – What makes this boiler special is that it is fitted with a highly intelligent piece of technology. Viessman has equipped their 35kW 100w combi boilers with the Lambda Pro combustion system. Ensuring continuous clean and efficient combustion, this component will automatically detect and adjust to all gas types. This could prove to be an invaluable convenience during the eventual transition to a 20% H2 blend.
  • Inox Heat Exchanger – Viessmann has fitted several of their recent boiler models with this highly efficient component. The corrosion-resistant stainless steel heat exchanger effortlessly converts energy into heat. The technology provides permanently high efficiency to extend the reliability of their boilers.


As an ErP A-rated and 94% efficiency-rated boiler, there is plenty to enjoy about the Vitodens 100-W combi boiler. Not only will the boiler operate at maximum efficiency for an extended duration, but the transition to H2 fuel will be effortless with the existing components prepared for the switch.

Certified and equipped to run on this fuel of the future, Viessmann has presented a hydrogen-powered boiler that is hydrogen-ready. What’s more, it is one of the most efficient and convenient on the market right now. 

If you’re interested in finding out more about this boiler, read our full review of the Viessmann Vitodens 35kW 100W combi boiler

Get Your FREE Online Quote Today!
Save up to £590 PER YEAR on your heating bills.
Quote in 30 seconds. No obligation. Next Day installation.
Save up to £590 PER YEAR!
0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *

© Copyright - Boilerhut 2024 - Registered in England & Wales, company number: 8615540 Vat number: GB- 169 0436 95