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When Are Gas Boilers Being Phased Out & What Will Replace Them?

Gas boilers will be phased out in the UK due to the government's bid to reach Net Zero carbon emissions by 2050. When the phasing out process starts remains unconfirmed, but it looks like the installation of new gas boilers will stop from 2035 for new build homes.

A gas boiler emits more CO2 than any other boiler type, so it's perhaps no surprise that their removal is key to meeting the zero-carbon target. Combining the emissions of all UK homes equates to twice the emissions of all the country's gas-fired power stations, so the country is looking to reduce and, eventually, stop the installation of gas boilers. 

But, what will replace them? This article will detail all you need to know about the phasing out of gas boilers and the clean energy alternatives that will replace them.

When Are Gas Boilers Being Phased Out?

The installation of new gas boilers is being phased out for both new homes and old houses. 

Two dates associated with these landmarks are 2025 and 2035, although they are both yet to be confirmed.

New homes

2025 will see the start of the government's Future Homes Standard initiative, a list of standards that all new residential buildings must meet. These standards are mostly related to making all new buildings greener. This policy ensures that new homes produce 75-80% less carbon dioxide emissions than new buildings do currently.

The Future Homes Standard states that all new homes must contain low carbon heating systems, ensuring they are future-proofed and will produce fewer emissions. The plan also says that no gas boilers can be installed in new homes, implying that no gas network can be fitted.

However, the government’s Heat and Buildings Strategy, which was released in October 2021, conveyed doubt that this phasing could start in 2025. Instead of doubling down on its proposed 2025 target, it suggested that further review was required to determine whether this was possible.

Old homes

In the same Heat and Buildings Strategy, the government conveyed its ambition to stop new boilers from being installed in old homes by 2035. 

Instead, low-carbon alternatives to gas boilers will be installed whenever a boiler replacement is required. Again, this cut-off year has only been suggested and has not been made official.

Why Are Gas Boilers Being Phased Out?

Gas boilers are being phased out alongside other fossil fuel energy sources, as they release too many carbon emissions, which contribute to global warming. Gas boilers account for a large chunk of the UK's greenhouse gas emissions, with each gas boiler releasing 2.2 tonnes worth of carbon dioxide every year.

Primarily, gas boilers are being phased out due to the environmental impact, but there are several other reasons they are worse than green alternatives, such as electric boilers. 

Gas boilers are bulkier and more expensive to maintain than green alternatives. There's also the risk of a carbon monoxide leak with gas boilers. 

The phasing out of gas boilers also coincides with the global gas shortage, which has been caused by several factors, from COVID-19 to diplomatic relations between countries. This has caused energy prices to soar, reaching heights that are 335% higher within one year.

Therefore, there are many reasons why gas boilers are being phased out, besides the main environmental concerns.

Do I Have To Replace My Gas Boiler By 2025?

No, you don't have to replace your gas boiler by 2025. Not at all.

If you have a gas boiler installed before this date, you can use it until it needs to be replaced. 

There has been no suggestion, as of yet, that there will be an outright gas boiler ban. 

The 2025 date also only relates to the ban on the installation of gas boilers in new build residential properties, not the replacement of an existing boiler in your home.  

Although you can continue to use your gas boiler as normal once the phasing out has been completed, you will be encouraged to switch to a clean energy source once your gas boiler breaks. 

What Will Be The Alternative To Gas Boilers?

Heat pumps

Heat pumps work by drawing in hot and cold air from an external source, converting this energy, and using it to heat or cool an internal space. There are two main types of heat pumps: ground source heat pumps and air source heat pumps.

Ground source heat pumps

A ground source heat pump utilises the natural heat that is stored underground. It consists of a water pipe network buried underground, outside your home, and an above-ground heat pump. To harness the heat, hot water and anti-freeze are circulated through the pipe network, which absorbs the heat and takes it above ground.

This water and anti-freeze mix is then compressed, and a heat exchanger extracts the heat. This energy is then sent to the heat pump, which supplies your radiators and hot water cylinder with energy.

Air source heat pumps

An air-source heat pump absorbs hot air from outside using a fan. This hot air heats a liquid refrigerant found inside the heat pump and turns it into a gas. This gas is then sent through a compressor, creating more heat energy. Lastly, the hot gas goes through a heat exchanger, where it is used to warm up cool air and water.

This warmed air and water mix is then used in your home heating system while the refrigerant is condensed back into a liquid, and the air source heat pump process starts again.

The pros and cons of heat pumps


  • Although expensive to install, heat pumps could save you money on energy bills as they produce energy efficiently, and the heat pumps themselves have very low maintenance costs.

  • The only power needed for both types of heat pumps is electrical. No fossil fuels are needed for operational purposes, meaning that they are much more environmentally friendly than the likes of a gas boiler.

  • Both types of heat pumps offer high durability. Ground source heat pumps can last from 20-25 years, while air source heat pumps last around 20 years.


  • Heat pumps deliver heat at a lower temperature than an oil or gas boiler. For this reason, you need to have your heat pump running for longer periods to heat your house to the same level as that of a gas boiler.
  • You will also require adjustments such as increased size of radiators, as they will not emit as much heat due to the lower water temperature etc. 
  • You'll need to make space in your garden for either an above-ground heat pump or a condenser unit for both a ground source and an air source heat pump.
  • Depending on the current pipework in your home, you may need to upgrade your heating system to prepare for the installation of the heat pump.
  • There will be a lot of disruption when installing, including building works and significant pipe runs in some instances.

Heat network systems

A heat network system - sometimes referred to as a district heating system - is effectively one big central heating system that supplies power to numerous buildings via underground insulated pipes.

The heat source could be many things, from waste heat from a shopping centre to geothermal and heat pumps. They are good for the environment as they utilise heat that would otherwise be wasted and can be used to heat several buildings simultaneously.


  • There is no need for individual boilers in each home with a heat network system. It requires less power to convert heat from one source than lots of different individual boilers. They, therefore, produce fewer greenhouse gas emissions.

  • Heat network systems work well in build-up areas, such as city centres.


  • Requires high installation and maintenance costs.

  • Power levels can be inconsistent. Those who rely on heat network systems have often reported periods without hot water.

Hydrogen boilers

Hydrogen boilers operate very similarly to a gas boiler, the only difference being that they heat your home by burning both hydrogen and natural gas instead of just natural gas. Hydrogen ready boilers are currently available and are based on a switch to a 20% hydrogen and 80% natural gas mix in the future.

When gas distribution networks eventually convert from natural gas to hydrogen in the future, these boiler types will be able to operate on 100% hydrogen.


  • Water is the only byproduct of burning hydrogen - no carbon emissions are created, so hydrogen-ready boilers are considered a green solution.

  • Hydrogen boilers are very similar to gas boilers, making them an easy switch for homeowners.

  • Unlike natural gas, hydrogen is non-toxic. It does not produce carbon dioxide or monoxide.


  • Hydrogen is highly flammable, and special protective measures must be installed during the installation of hydrogen boilers.

  • Hydrogen is very light, which makes it difficult to store.

Electric radiators 

Electric radiators are not connected to any main heating supply and work as standalone heating systems. They are filled with either dry elements or thermal fluid, and heat is created through radiation and convection. Electric radiators are highly efficient and release no greenhouse gases during operation, making them better for the environment than gas.


  • Electric radiators are highly efficient, as every energy watt produced is used for heating.

  • Easily installed and maintained - you don't need a professional to fit electric radiators, nor do you need one to perform annual checks.
  • They provide accurate temperature control and normally come with an easy-to-use thermostat and smart control options.


  • Electricity is more expensive than gas, meaning higher energy bills.

Biomass boilers

Biomass boilers are similar to traditional gas boilers, except instead of gas, they operate on such fuel as wood pellets and chips. The heat generated by the burning of this fuel can heat hot water and provide your central heating system with power.


  • Biomass boilers are considered good for the environment as they burn fuel that can easily be replaced. For example, although chopping down trees for fuel is technically bad for the environment, trees can be grown back quickly, whereas it takes thousands of years for the likes of coal to be renewed.

  • Wood is a cheap fuel, and its prices will remain steady - unlike gas.


  • They tend to be bulky and often require a separate room. You'll also need to consider where to store the fuel.

Solar thermal panels

Like solar panels, solar thermal panels harness the heat energy from the sun, but instead of using it to produce electricity, they are used to create hot water. Used alongside the likes of a heat pump, thermal solar panels can be used to reduce the carbon footprint of your entire home.


  • Have a greater efficiency than PV solar panels because the energy doesn't have to be converted into electricity.

  • Can work in cold climates.

  • Cheaper than PV panels.


  • It can only be used to create hot water.

  • High start-up costs.


Can I replace my gas boiler with an electric boiler?

An electric boiler is a suitable replacement for a gas boiler, and it can be adapted to fit your current home heating system. That said, electricity costs are higher than gas in the UK right now and often can need adjustments like the mains upgrading, depending on your current power incoming to the property. For more information, read our guide on the pros and cons of electric boilers & gas boilers

Can modern gas boilers run on hydrogen?

New gas boilers are built to be 'hydrogen ready', meaning that they can currently run on a mixture of 20% hydrogen and 80% natural gas and will be able to run on 100% hydrogen heating in the future.

Are heat pumps cheaper to run than gas boilers?

Depending on how well insulated your home is, heat pumps can be cheaper to run than gas boilers, as they use existing external heat to warm your home, whereas you have to pay for a gas boiler to generate heat.

Final Thoughts

Although it remains unclear when exactly gas boilers will be phased out, it's something that every household will need to be ready for in the coming decades. Given the sheer amount of CO2 that gas boilers produce, on top of the mounting price of gas, it would be wise to switch to a greener heating system sooner rather than later.

By installing a hydrogen-ready boiler, you can have your home running on renewable energy in no time. Get a boiler quote from BOXT today to find the perfect boiler for your home.

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