Hydrogen Boiler Guide and What is a Hydrogen Ready Boiler?

Hydrogen ready boilers for home heating?

In the UK and worldwide, people are thinking more about sustainability and how we can reduce our carbon footprint.

Hydrogen-ready boilers could be part of the solution as a replacement for natural gas boilers.

A hydrogen-ready boiler is a boiler that can be converted to run on 100% hydrogen with a few small changes. Fully hydrogen gas boilers are still in the prototype stage and currently aren’t ready to run on 100% hydrogen, but may be able to in the future.

Why is a boiler that can run on hydrogen important?

Both consumers and businesses actively seek to improve their energy efficiency to help preserve the environment. In the future, a hydrogen-powered boiler using green hydrogen could be a low-carbon alternative to gas boilers.

Currently, though, as full hydrogen boilers aren’t sold yet but, there are other ways to help us reduce carbon emissions and live in a more eco-friendly manner: if you are unsure which is best for your home, read our heat pumps vs boiler page for more information.

Why hydrogen-ready boilers for home heating?

Hydrogen-ready boilers, to 20%, are just one option in the heating industry and in the search for alternative fuel sources such as electric boilers, air-source heat pumps, and ground-source heat pumps.

100% hydrogen gas boilers, though are not ready yet as burning hydrogen gas in our homes is still a long way off, but these new low-carbon boilers could reduce air pollution and help us meet net-zero carbon targets if they go ahead.

What is a hydrogen-ready gas boiler?

A hydrogen-ready boiler is a type of boiler system that can burn both natural gas and hydrogen in order to generate heating.

How do hydrogen-ready boilers work?

Hydrogen-ready boilers are designed to work in a similar manner to gas boilers and other than their modified flame detector, most of their construction, features, and functions resemble that of gas boilers.

A Gas Safe registered engineer should be able to perform this task after receiving adequate training. Currently, it is not possible to make a combi boiler hydrogen ready past 20%.

The process for how a prototype hydrogen-ready boiler works is as follows:

• 1. Both oxygen and hydrogen enter the boiler system. The oxygen will come from the air and the hydrogen will be sourced from the connected mains supply via the boiler’s gas inlet contains a valve which regulates the amount of each gas that can enter the boiler. The amount of gas will affect the size of the flame ignited.

• 2. Secondly, the gases are combined and ignited in a catalytic burner. As hydrogen is more flammable in comparison to natural gas, the burners on hydrogen boilers are uniquely designed to limit the flame if too much gas flows through, as a safety precaution. Hydrogen boilers are also built with a flame detection component for safety, as hydrogen flames are not visible. 

• 3. In the next step of the process, the hot flue gasses which are created as a result of the combustion enter the system’s heat exchanger. This component features a number of pipes for the hot gas to travel through. Cold water surrounds these pipes and as the hot gasses pass through them, the water becomes heated. This heated water can then be transported through to your radiators and taps as required.

• 4. Lastly, water is produced as a by-product of the burning of hydrogen and oxygen. A condensate is required for this liquid to be dispelled from the system. The hot hydrogen and oxygen gases can exit the system via the flue, as well as some NOx emissions.

All gas appliances in the home since 1996 are able to receive up to 23% hydrogen mixed with natural gas.

What is the difference between a hydrogen-ready boiler and a 100% hydrogen boiler?

Many people get hydrogen blend-ready boilers confused with full hydrogen-ready boilers, hydrogen boilers or boilers that use hydrogen fuel cells.

However, hydrogen blend-ready boilers use a 20% blend of hydrogen and natural gas, and they can use both gases as fuel. In contrast, hydrogen boilers use hydrogen solely as fuel instead of natural gas. 

If they become available, hydrogen-ready boilers are thought to be the first step in the transition to more low-carbon heating. These systems can still use natural gas as a fuel, but they will also be able to utilise hydrogen if a 100% hydrogen network is introduced.

Are 100% hydrogen boilers currently available to purchase?

Hydrogen boilers are not currently available to purchase just yet. Boiler manufacturers such as Viessmann, Worcester Bosch, Baxi, and Ideal have developed prototype hydrogen combi boiler systems, but research and trials of this form of heating are still ongoing.

In the UK, the government is actively working with researchers to test hydrogen as a fuel for boilers. Trials for production methods are also taking place.

Here’s a breakdown of some of the tests and trials underway:

• HyDeploy – This is a project being conducted at Keele University in Staffordshire. A 20:80 blend of hydrogen and natural gas is being trailed with 100 homes and 30 faculty buildings being supplied with this mix.

• Hydrogen Supply Programme – In 2020, the UK government made a pledge of £20 million towards the Hydrogen Supply Project. This is an initiative which helped to fund the HyDeploy project that took place at Keele University.

• Hy4Heat – This project is trailing the possibility of a 100% hydrogen network. As of 2020, the Hy4Heat scheme was reported to be making encouraging progress. It is currently testing the safety of using hydrogen as a fuel to power appliances. Programme leaders are also seeking to ensure that engineers get the necessary training to install and work on these hydrogen boilers.

• The National Grid Hydrogen Project – The National Grid has joined forces with SGN, OFGEM and the Scottish Government to trial hydrogen on the network grid.

This project is expected to feature the fitting of hydrogen boilers in over 300 properties in Fife, Scotland. These households will also be fitted with cookers and other appliances, and they will be fuelled with hydrogen by the end of 2022. The trial process is set to last approximately four years in total; around 1,000 properties will be included in the project.

When will hydrogen boilers be ready for homes in the UK?

The process of introducing hydrogen boilers is likely to take some time, especially since testing and trial processes are still underway. Northern Gas Networks developed a hydrogen home that runs on 100% hydrogen.

Most hydrogen boilers are still in their prototype stage. Plus, even when these systems are officially launched, converting all gas boilers to hydrogen systems is likely to be a time-consuming process, even if the job is small.

Additionally, there is currently a supply issue within the UK, which means that there is not enough hydrogen to supply to everyone’s homes. This is where the air source vs ground source heat pump debate is likely to be thrown into the mix again.

Although there seem to be quite a few hurdles that need to be crossed before hydrogen boilers are introduced, the industry is making gradual progress.

Are natural gas boilers being banned?

This is a key question on many homeowners’ minds as we are being increasingly encouraged to move away from the use of fossil fuels as energy sources. 

In 2019, the UK government released plans to ban the installation of gas boilers in newly built homes from the year 2025, in line with strict sustainability targets.

Heat pumps are currently being pushed by the government but just don’t have the heating abilities of natural gas boilers.

Can gas boilers be converted to hydrogen boilers?

Currently, gas boilers in UK homes can not be converted to hydrogen boilers.

They can, though, currently run on up to 20% hydrogen mixed with natural gas. The next step in the process is the hydrogen-ready gas boiler, which can be converted further down the line by a trained engineer.

Gas condensing boilers are highly rated for their energy efficiency and are the best type of boiler for home heating as they are able to recycle latent heat instead of allowing it to be wasted.

According to the Energy Saving Trust, a new gas boiler could help to lower your carbon footprint significantly. 

What should I do?

If your boiler is over 10 years old, its level of energy efficiency is likely to be low and it may be time for a replacement boiler.

Here at Boiler Central, we install a range of high-quality, A-rated gas boilers from some of the leading names in the industry – such as Viessmann, Worcester Bosch, and Ideal.

We could provide you with a first-class boiler installation at a time that suits you.

Enter a few details about your home and heating needs into our free online quote tool, and in just a few moments, you’ll receive your free quote for your new boiler installation from Boiler Central, as well as a recommendation for a suitable boiler for you.