Best Combi Boiler In 2023 (Top 8 & Rated)

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Step into the world of ultimate home comfort and efficiency with our comprehensive guide on the top 8 best combi boilers in the UK. Discover top-rated options that guarantee optimal performance, ensuring a cosy and energy-efficient living space.

Lets get into it!

Summary Of Best Combi Boiler

Best Gas Combi Boiler: Worcester Greenstar 8000 Life Combi Gas Boiler – This boiler offers high efficiency and reliability with advanced features for optimal performance.

Best Electric Combi Boiler: Trianco Aztec Electric Mini Combi Combination Boiler – This electric boiler provides efficient heating and hot water supply in a compact design, suitable for smaller properties.

Best Compact Combi Boiler: Worcester Greenstar 32CDi Compact LPG Combination Boiler – This compact LPG boiler from Worcester is designed to fit within a standard kitchen cupboard, making it suitable for smaller spaces.

Best High-Output Combi Boiler: Keston Combi C30 Boiler – The Keston Combi C30 offers a high heating output, making it suitable for larger properties with higher hot water demand.

Best Combination Boiler Overall: Vaillant ecoFIT Pure Combination Gas Boiler – The Vaillant ecoFIT Pure combines efficiency, reliability, and user-friendly controls, providing excellent performance and heating comfort.

What Is A Combi Boiler?

What Is A Combi Boiler 1

A combi boiler, also known as a combination boiler, is a popular heating system found in many homes. It is a type of boiler that provides both hot water and central heating without the need for a separate water storage tank or cylinder.

Combi boilers work by heating water on demand as it flows directly from the main supply. When you turn on a hot water tap or switch on the heating, the new boiler ignites and heats the water using a heat exchanger.

This hot water is then delivered to your taps, showers, and radiators. Combi boilers are known for their compact size, energy efficiency, and the convenience of providing instant hot water without the need for a separate tank.

They are particularly suitable for smaller properties or homes with limited space

Best Combi Boiler

1. Worcester Greenstar 8000 Life Combi Gas Boiler

Worcester Greenstar 8000 Life
Worcester Greenstar 8000
  • High Efficiency
  • Reliable and Well-Built
  • Modern Design
  • EasyControl Compatibility
  • LPG Compatibility
  • Price

The Worcester Greenstar 8000 Life Combi Gas Boiler is a highly regarded heating system manufactured by Worcester Bosch. It is available in different models, offering various heating outputs and flow rates to suit different property sizes and hot water demands. Some key features and specifications of the Greenstar 8000 Life Combi Gas Boiler include:

Models: The range includes models with heating outputs of 30kW, 35kW, 40kW, and 50kW.

Efficiency: The Greenstar 8000 Life Combi Gas Boiler has an ErP efficiency rating of A, indicating high energy efficiency.

Dimensions: The new boiler has dimensions of approximately 780mm (height) x 440mm (width) x 365mm (depth).

Hot Water Flow Rate: The flow rate of hot water at a temperature difference of 40°C ranges from 10.7 to 20.3 litres per minute, depending on the model.

Control Options: The boiler is compatible with EasyControl, allowing for convenient control of heating and hot water.

Warranty: Worcester Bosch offers an impressive 12-year warranty on the Greenstar 8000 Life Combi Gas Boiler.

The Worcester Greenstar 8000 Life Combi Gas Boiler is recognized for its reliability, modern design, and ease of use and considered best boilers on the UK market. It is suitable for a range of property sizes and is compatible with a variety of control options.

2. Trianco Aztec Electric Mini Combi Combination Boiler 

Trianco Aztec Electric Mini Combi Combination Boiler
Trianco Aztec Combi Boiler
  • Compact Design
  • Immediate Hot Water Supply
  • Fully Controlled
  • No Pipework or Flue Kit Required
  • Electrical Power Requirement
  • Limited Heating Output

The Trianco Aztec Electric Mini Combi Combination Boiler 12kW is a highly efficient and compact electric boiler produced by Trianco. This boiler is specifically designed for compact spaces such as apartments, cabins, and garden rooms, where space is limited but a reliable heating and hot water solution is still required.

One of the notable advantages of the Trianco Aztec Electric Mini Combi Combination Boiler 12kW is its compact design. Its small size allows for easy installation in utility rooms, kitchen cupboards, or alongside kitchen wall cabinets. This makes it an ideal choice for projects with limited available space.

The boiler is powered by a corded electric source, eliminating the need for traditional fuels such as gas or oil. This can be advantageous for properties that do not have access to a main gas supply or prefer an alternative to traditional heating systems.

Despite its compact size, the Trianco Aztec Electric Mini Combi Combination Boiler 12kW provides an impressive heat output of 12 kilowatts, ensuring efficient and effective heating performance. It also offers a water heating output of 12 kilowatts, guaranteeing a steady supply of hot water for various domestic requirements.

3. Keston Combi C30 Boiler

Keston Combi C30 Boiler
Keston C30
  • High efficiency
  • Compact size
  • Dual functionality
  • Modulating capability
  • Twin flue system
  • Noise level

The Keston Combi C30 Boiler is a high-efficiency domestic condensing gas combination boiler manufactured by Keston. This boiler is designed to provide both heating and hot water in a single appliance, offering convenience and energy efficiency for residential applications.

The Keston Combi C30 Boiler comes with a range of features and benefits. It is a fan-powered, modulating boiler that ensures efficient and precise control of the heating output.

With its condensing technology, the boiler maximizes energy efficiency by recovering heat from the flue gases, resulting in lower energy consumption and reduced heating costs.

4. Vaillant ecoFIT Pure Combination Gas Boiler

Vaillant ecoFIT Pure Combination Gas Boiler
Vaillant ecoFIT
  • Compact Design
  • Installation Flexibility
  • Energy Efficiency
  • Easy Installation and Maintenance
  • Durability and Reliability
  • Availability

The Vaillant ecoFIT Pure Combination Gas Boiler is a highly efficient and versatile heating solution for homes of various sizes. With its compact size and cupboard-fit design, this boiler offers flexibility in installation, making it suitable for small spaces such as kitchen cupboards. Whether you need a reliable heating solution for a cosy apartment or a compact home, the ecoFIT Pure Combination Boiler fits the bill.

One of the standout features of this boiler is its top and rear flue options, which provide installation flexibility and ensure that the boiler can be conveniently placed in different locations within your home. This adaptability is a great advantage, allowing you to optimize space utilization while meeting your specific installation requirements.

The Vaillant ecoFIT Pure Combination Boiler is built to last, thanks to its high-performance automotive-grade aluminium heat exchanger. This heat exchanger not only ensures exceptional durability but also offers improved energy efficiency, helping to reduce energy bills over time. Additionally, the aluminium construction makes maintenance easier, further enhancing the longevity and reliability of the product.

5. Ideal Logic+ C35 Combination Boiler

Ideal Logic C35 Combination Boiler
Ideal Logic+
  • Wide range of fueling options
  • Compatibility with additional controls
  • Compact cupboard fit
  • Large digital display
  • Energy Saving Trust endorsed
  • Fully modulating operation
  • Limited availability

The Ideal Logic+ C35 Combination Boiler Natural Gas ErP 215441 is a heating appliance designed for residential use. It is a compact and versatile boiler that offers a wide range of features and benefits. This boiler provides a variety of fueling options, allowing for flexibility in installation.

It is compatible with different types of additional controls, including OpenTherm controls, which provide advanced functionality and improved energy efficiency. The compact size of the boiler makes it suitable for installation in kitchen cupboards or other small spaces.

One notable feature of the Ideal Logic+ C35 Combination Boiler is its large digital display, which offers clear visibility and ease of use. This display enhances the user experience by providing important information about the boiler’s operation and settings. The boiler also includes a PRV (Pressure Relief Valve) wall outlet pipe for added convenience.

Energy efficiency is a key aspect of this boiler, as it is endorsed by the Energy Saving Trust. With its fully modulating operation, the boiler adjusts its output to meet the heating demands, resulting in optimal energy usage and reduced energy bills.

6. Elnur Mattira MAC15 3-15kW Electric Combination Boiler

Elnur Mattira MAC15 3 15kW Electric Combination Boiler
Elnur Mattira Combi Boiler
  • Wide range of outputs for heating needs
  • Automatic modulation for energy savings
  • Compatibility with both single-phase and 3-phase systems
  • Compatible with underfloor heating
  • Insulated stainless steel DHW tank
  • Reliance on electricity

The Elnur Mattira MAC15 Electric Combination Boiler is a highly advanced and efficient electric boiler designed for heating and hot water needs. With its range of features and benefits, it offers a reliable and convenient solution for residential heating systems. Here’s a detailed product review:

Design and Features: The MAC15 boiler features a sleek and compact design, making it suitable for wall-mounted installation. It comes with a 50L domestic hot water tank made of insulated stainless steel, ensuring efficient heat retention and reducing energy wastage.

The boiler is compatible with both single-phase and 3-phase electrical supplies, providing flexibility for installation in various settings. It is also designed to work with underfloor heating systems, offering an additional heating option. The boiler is powder coated in RAL9010, giving it a clean and attractive appearance.

Efficiency and Energy Savings: The MAC15 boiler incorporates advanced control board technology, enabling automatic modulation of the heating output based on demand. This feature ensures energy savings by matching the heating needs precisely, thereby minimizing energy waste.

While specific efficiency ratings are not provided in the available information, the modulation system and energy-saving design contribute to overall efficiency.

Installation and Ease of Use: The boiler comes with all the necessary components required for operation, including a template that facilitates the installation process. Installers will appreciate the ease and convenience offered by the boiler’s comprehensive package.

The user-friendly digital display allows easy monitoring and control of the boiler’s settings, providing a hassle-free experience for homeowners.

7. Morco LPG 24kW Condensing Combi Boiler

Morco Combination Boiler
  • High Output Capacity
  • Compact Design
  • Versatile Flue Options
  • Electronic Ignition
  • Fan-Assisted Combustion
  • Minimum Water Pressure Requirement
  • LPG Fuel Requirement

The Morco GB24 LPG Vertical Flue and Fitting Kit Combi Boiler is an excellent heating appliance that provides efficient heating and hot water solutions. Here is a comprehensive review of this product.

One of the standout features of the Morco GB24 boiler is its impressive output capacity of 24.2 kW, ensuring optimal heating performance and a sufficient supply of hot water for various household needs. Whether it’s heating your entire home or providing hot water for daily activities, this boiler delivers reliable results.

The compact design of the boiler is another positive aspect. With dimensions of 700mm in height, 395mm in width, and 285mm in depth, it is suitable for installations in limited spaces. This flexibility allows homeowners to integrate the boiler into their existing setup without major modifications.

The inclusion of a vertical flue and fitting kit is a convenient addition to the package. The vertical flue option offers installation versatility, allowing users to choose between vertical and horizontal flue configurations depending on their specific requirements. The provided kit ensures a hassle-free installation process, making it easier for both professional installers and DIY enthusiasts.

8. Worcester Greenstar 32CDi Compact LPG Combination Boiler

Worcester 7733600058 Greenstar 32CDi Compact LPG Combination Boiler
Worcester Greenstar 32CDi
  • Compact Design
  • User-Friendly Displays
  • High Hot Water Flow Rate
  • Frost Protection
  • Energy Efficiency
  • LPG Fuel Requirement

The Worcester Greenstar 32CDi Compact LPG Combination Boiler is a reliable and efficient heating solution suitable for small, medium, and large-sized homes with one or two bathrooms. Its compact design allows for easy installation within a standard kitchen cupboard, making it a space-saving choice for homeowners.

One of the standout features of this boiler is its user-friendly displays, which make it incredibly easy to operate. The clear temperature display and simple boiler control knobs provide convenience and allow for fine-tuning the hot water settings according to personal comfort preferences.

With its high hot water flow rate of 11.5 litres per minute at a 40°C temperature rise, the Worcester Greenstar 32CDi Compact ensures a continuous supply of hot water, even in homes with multiple bathrooms. This feature is a great advantage for households where hot water demand is high.

Another great choice for the best boilers on the UK market!

What Are The Advantage And Disadvantages Of a Combi Boiler?

What Are The Advantage And Disadvantages Of a Combi Boiler 1

Advantages of Combi Boilers

Energy Efficiency: Combi boilers are highly efficient, with condensing models having an efficiency rating of 90-94%. This can lead to lower energy bills compared to older conventional boilers.

Space-Saving Design: Combi boilers are compact and don’t require additional space for hot water cylinders or cold water storage tanks. This makes them ideal for properties with limited space.

Instant Hot Water: Combi boilers provide hot water on demand, eliminating the need for a separate hot water cylinder. This means you have instant access to hot water whenever you need it.

Easy Installation: Combi boilers are relatively easy to install, especially in comparison to system boilers. The absence of external water tanks simplifies the installation process.

Disadvantages of Combi Boilers

Limited Hot Water Flow Rate: Combi boilers have a limited hot water flow rate, which means they may struggle to meet the demands of multiple showers or baths being used simultaneously. This can result in a temporary drop in water pressure.

Unsuitable for High Water Demand: Combi boilers may not be suitable for properties with high hot water demand, such as large households with multiple bathrooms.

Reliant on Mains Water Pressure: Combi boilers rely on mains water pressure to provide hot water, so if the mains pressure is low, it can affect the performance of the boiler.

Heating Interruption During Maintenance: If a combi boiler requires maintenance or repairs, it may result in a temporary loss of both the heating and hot water supply.

Top 10 Best Combi Boiler Brands On The Market

When it comes to choosing a combi boiler for your home, selecting from the best combi boiler brands can provide you with peace of mind and reliable performance.

These brands have established themselves in the market by delivering efficient heating and hot water solutions, along with a reputation for quality and durability

Worcester Bosch: Worcester Bosch is a highly regarded and reliable brand, known for its high-quality combi boilers.

Vaillant: Vaillant is another reputable brand that offers a wide range of efficient and reliable combi boilers.

Ideal: Ideal is a well-established brand known for producing reliable and affordable combi boilers.

Viessmann: Viessmann is a leading brand that offers high-quality and energy-efficient combi boilers.

Baxi: Baxi is a trusted brand known for its reliable and efficient combi boilers.

Alpha: Alpha is a brand that focuses on energy-efficient and innovative combi boilers, offering a range of models to suit different needs.

Glow-worm: Glow-worm is known for its affordable and reliable combi boilers, providing efficient heating and hot water solutions.

Potterton: Potterton offers a range of combi boilers that are known for their reliability and energy efficiency.

Vokèra: Vokèra is a brand that specializes in affordable and efficient combi boilers, providing reliable heating and hot water solutions.

Ferroli: Ferroli offers a variety of combi boilers known for their energy efficiency and reliability

Is a Combi Boiler Cheaper To Run Than a Tank?

Is a Combi Boiler Cheaper To Run Than a Tank 1

Yes, a combi boiler is generally cheaper to run compared to a tank-based system.

The great thing about combi boilers is that they are highly energy efficient. In fact, condensing combi boilers have an efficiency rating of 92% or even higher.

This means they can convert a larger portion of the energy they use into actual heat, which results in lower energy consumption and reduced running costs.

Another advantage of combi boilers is that they eliminate the need for storing hot water in a tank, which can lead to heat loss. By providing hot water on demand, combi boilers help improve overall efficiency and save you money.

However, keep in mind that the actual cost savings will depend on factors such as your hot water usage, usage patterns, and installation costs.

Does a Combi Boiler Use a Lot of Gas?

Does a Combi Boiler Use a Lot of Gas 1

Yes, a combi boiler does use gas. The amount of gas consumed by a combi boiler can vary depending on factors such as the size of the boiler, its efficiency, and the duration of its usage.

Boiler sizes are measured in kilowatts (kW), and they can range from 24 kW to around 40 kW. The gas consumption of an average 35 kWh gas combi boiler in the UK is approximately 35 kilowatt-hours worth of gas per hour of usage.

However, it’s important to note that actual gas consumption can be influenced by factors such as the efficiency rating of the boiler and the temperature settings used.

It’s recommended to consult the boiler manufacturer’s specifications or consult with a heating engineer for a more accurate estimation of gas usage specific to your combi boiler model.


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