Are you tired of your old boiler increasing your energy bills? You’re not alone. Many people in the UK face high costs to heat their homes, especially during cold months. It’s a common problem that needs a good solution.

Our article will guide you through the best boilers available in the UK that are kind on both your wallet and the environment. 

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How Is Boiler Efficiency measured?

The ERP efficiency rating plays a key role in this process. This rating shows how well a boiler uses energy to produce heat.

A high ERP score means the boiler is more energy efficient. Experts look at how much fuel a boiler uses and compare it with the heat it gives out to get this rating.

An A+++ classification stands as the top mark for energy use in boilers. Boilers with an A+++ label are the best at turning fuel into heating without wasting much energy. By using less power, they save people money on bills, up to £522 every year.

Tools like flue gas heat recovery systems help these high-rated boilers use even less energy by capturing wasted heat and putting it back into the house’s heating system.

Why is it important?

Having an efficient boiler saves people a lot of money. A top-rated efficient boiler can put up to £522 back in your pocket every year. This is because these boilers use less gas or oil to heat your home and water, cutting down on energy bills.

Boilers must also meet certain standards now. All new boilers in the UK have to be condensing models. These are much better for the environment than old kinds because they waste less energy.

Choosing a high-efficiency boiler means doing something good for the planet while saving cash.

Now let’s look at the most efficient boiler options available.

Most Efficient Boiler Options

Explore the top options for efficient boilers: combi, system, and regular.
Choose wisely based on your heating and hot water needs.

Combi boilers

Combi boilers give both heating and hot water without needing a separate tank. These devices are great for saving space in your house. Some top efficient models include the Worcester Bosch Greenstar 8000, Ideal Logic Max, and Ariston ALTEAS ONE NET.

They use less gas or oil to run, making them kinder to the environment.

Switching to an A-rated combi boiler can cut your energy bills by up to £522 each year. Since all new boilers must be condensing types, they capture more heat that would escape from old systems.

This means you get more warmth for your money and reduce waste at the same time.

System boilers

Shifting focus from combi boilers, we now explore system boilers. These units need a hot water storage tank to function. This makes them perfect for homes that use a lot of water at the same time.

In the UK, all system boilers must be condensing types. This rule ensures they capture more heat from burn gases and are thus more efficient.

A-rated models are among the most efficient, boasting an efficiency rate over 90%. Upgrading from an old G-rated model to an A-rated one could save homeowners up to £320 annually on heating costs.

System boilers work great with solar energy systems too, making them even better for reducing energy bills and cutting down carbon footprints.

Regular boilers

Regular boilers, also known as conventional boilers, need a hot water storage cylinder and a cold water tank. They suit homes with multiple bathrooms where a lot of hot water gets used at the same time.

These boilers are great for places with low water pressure. Since all UK boilers must be condensing, regular boilers capture heat from exhaust gases that would otherwise escape. This means they use less energy and help reduce bills.

These systems work well with solar water heating systems to save on hot water costs. Regular boilers might not be the newest kind but remain a good choice for large families or homes without strong mains pressure.

They support both radiator and underfloor heating systems, making them versatile in meeting various household needs.

Factors to Consider Before
Choosing a New Boiler

Before choosing a new boiler, consider the type of boiler, fuel and emissions, price and installation costs, warranty
and customer service, energy efficiency and environmental impact.

Type of boiler

Choosing the right type of water heater depends on your home’s needs. Combi, system, and regular models are common options in the UK. Each has unique features to match different household sizes and demands for hot water and space warming.

Combi heaters work well for small houses or flats without much room for extra equipment. They heat water straight from the mains whenever you turn on a tap. System models need more space because they have a separate cylinder to store hot liquid but provide faster access to it across larger homes.

Regular types also use these cylinders but require an additional cold water storage tank, making them better suited for very large properties with higher water usage.

Fuel and emissions

Boilers can be powered by natural gas, oil, or electricity. Natural gas is the most common fuel for boilers in the UK due to its efficiency and lower emissions. It releases fewer greenhouse gases compared to other fossil fuels like coal and oil.

When it comes to emissions reduction, choosing a boiler with a high ERP rating and low energy consumption is crucial in minimising environmental impact and reducing fuel costs. Investing in an A-rated efficient boiler can save homeowners up to £522 per year on fuel costs while significantly cutting down on carbon footprint.

Top Energy Efficient Boilers

Viessmann Vitodens 100-W

The Viessmann Vitodens 100-W offers an impressive output range of 19-25kW, with a remarkable 94% efficiency. Moreover, it comes with a warranty that can extend up to 12 years, providing long-term peace of mind.

Viessmann Vitodens 100-W offers exceptional energy efficiency and reliability for homeowners.

Worcester Bosch Greenstar 4000

The Worcester Bosch Greenstar 4000 has an output range of 12-24kW, with an impressive efficiency of 93%-94%. 

This boiler offers energy-efficient heating solutions and reliable performance, making it a cost-effective choice for households looking to save on their heating bills. The Worcester Bosch Greenstar 4000 is designed to provide carbon-neutral heating using energy sources such as biomass fuels or mains gas, aligning with the growing demand for eco-friendly and sustainable home heating options.

With its advanced features and long warranty period, this boiler stands out as a top contender for those seeking an efficient and durable heating solution.

Baxi 800

The Baxi 800 has an impressive output range of 21.2-26.4kW, with a high efficiency of 93%. It comes with a substantial warranty of 10 years, offering long-term peace of mind to homeowners.

The price range is between £858 and £1,205, making it an attractive option in terms of both performance and affordability. When considering the top combi boilers for saving money, the Baxi 800 stands out as a reliable and cost-effective choice.

Origin Provides You With The Best Boiler Brands For Installation

A high-quality boiler deserves a professional installation. Our certified heating engineers ensure your new boiler is installed to the highest standards, maximising its efficiency and lifespan. We handle everything from removing your old boiler to installing and testing your new system, providing a hassle-free experience.

Ready to upgrade your heating system? Contact Origin today for a free consultation and discover the best boiler options for your home. Our dedicated team ensures you receive the best products and services, tailored to your needs.

Remember that choosing an efficient boiler tailored to your housing situation is key to unlocking cost-saving potential and reducing carbon footprint.


Energy-efficient boilers in the UK have high Seasonal Efficiency of Domestic Boilers in the UK (SEDBUK) ratings, meaning they use less gas or oil to produce hot water and heating, saving you money on bills.

Yes, solar panels can heat your hot water cylinder using clean energy from the sun, reducing how much gas or electricity your boiler needs.

Yes! Alternatives include biomass boilers that burn wood pellets, ground source heat pumps that extract heat from underground, air source heat pumps that take air from outside, and hydrogen fuel options for a carbon-free future.

Insulating your hot water tank with lagging keeps water hotter for longer periods by reducing heat loss. This means your boiler doesn’t work as hard, saving you money and making it more efficient.

Upgrading an old gas boiler to a newer model with higher boiler efficiency ratings or switching to an environmentally friendly system like ground source heat pumps can significantly reduce your home’s carbon footprint while ensuring a consistent domestic hot water supply.