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Last updated: 8th May, 2024


What Type of Boiler Is Right for Me?

What Type of Boiler Is Right for Me?

Key takeaways

  • Understand the differences between combi, system, heat-only, and electric boilers to choose the ideal type for your home.
  • Consider boiler efficiency, environmental impact, and installation requirements based on your home's specific needs.
  • Research the best boiler brands and associated costs to make an informed decision on the right boiler for your home.

Choosing the right type of boiler for your home can be a challenging decision, as there are several factors to consider, such as your heating needs, available space, and budget. Our guide explores the different types of boilers available, including combi, system, and regular boilers, and provides practical advice on how to choose the right one for your home.

Selecting the right boiler for your home can be a daunting task, especially with the wide array of options available in the market. Understanding the different types of boilers and their unique features is crucial in making an informed decision. 

By comparing combi, system, heat-only, and electric boilers, you can better determine which type of boiler is the most suitable for your household needs and preferences.

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Boilers not only serve as a source of heat for your home but also provide hot water on demand. Efficiency and environmental impact should be taken into consideration, as well as the size of your home and specific installation requirements. 

Factors to consider include the number of bathrooms, mains pressure, and the age of your home. It's also worth doing some research on the best boiler brands and associated costs to ensure a good return on your investment.

Understanding Boilers

When selecting the right boiler for your home, it is essential to understand the various types of boilers and their unique advantages. Boilers play a crucial role in heating your home, providing hot water and contributing to energy efficiency. There are three main types of boilers: combi, conventional, and system boilers.

Combi boilers are a popular choice for many homeowners due to their space-saving design. A single unit provides both hot water and space heating, eliminating the need for a separate hot water cylinder and cold water storage tank. This makes them an ideal option for smaller homes or those with limited space.

On the other hand, conventional boilers are more suitable for larger households with multiple bathrooms or an older house. These boilers require a hot water cylinder and a cold water storage tank, which can take up a considerable amount of space. However, they can ensure a steady supply of hot water to multiple outlets simultaneously, even with low mains pressure.

System boilers are another option to consider. Like conventional boilers, they require a hot water cylinder but do not need a cold water storage tank. This feature makes them more space-efficient than conventional boilers, and they are still capable of providing ample hot water to multiple outlets.

In addition to boiler types, it is important to factor in other considerations, such as energy efficiency and fuel source. Most modern gas boilers are condensing boilers, which extract more heat from the exhaust gases and go a long way in reducing energy consumption, making them an eco-friendly choice.

Ultimately, the right boiler for you depends on your specific needs and circumstances. Take into account your household size, the number of bathrooms, available space, and energy efficiency requirements. By carefully considering these factors, you can choose the best boiler type for your home, ensuring a warm, comfortable space and a reliable supply of hot water.

Combi Boilers-

A combi boiler, short for combination boiler, is a popular choice for providing both central heating and hot water in your home. With a sleek and compact design, it combines these two functions in a single unit, ensuring high efficiency and instant hot water whenever needed.

The Pros and Cons of Combi Boilers


  • Compact size: Combi boilers are small and don't require additional space for a separate hot water cylinder or storage tank. This makes them an ideal choice for smaller homes with limited space.

  • Efficiency: As these boilers provide hot water directly from the mains pressure, they tend to be more energy-efficient compared to other boiler types.

  • Instant hot water: With a combi boiler, hot water is available on demand, meaning you'll have access to hot water for your shower or taps without having to wait for a storage tank to heat up.

  • Cost-effective: Since they have fewer components and do not require a separate hot water storage system, combi boilers are generally cheaper to install and maintain.


  • Hot water demand: Combi boilers may struggle to provide enough hot water when multiple taps or showers are in use simultaneously. This can be a problem in larger households with multiple bathrooms.

  • Limited flexibility: Combi boilers are not compatible with some types of showers, such as power showers, which may limit your options when installing or upgrading your shower.

Overall, combi boilers' suitability largely depends on the size of your household and your hot water needs. They're an excellent choice for smaller homes with a single bathroom, while larger households may require alternative options to meet their hot water demands.

System Boilers

System boilers are an excellent choice for homeowners looking for a reliable, efficient, and powerful boiler system. This type of boiler consists of a central boiler unit that heats water, which is then stored in a hot water cylinder. It is connected to a separate cold water tank and a pump, ensuring a steady flow rate and a constant supply of hot water.

The Pros and Cons of a System Boiler

There are several advantages to choosing a system boiler for your home. Firstly, these boilers have a separate hot water tank, enabling them to provide a larger volume of hot water simultaneously compared to a combi boiler. This is particularly beneficial for households with multiple bathrooms and higher hot water demands. Additionally, system boilers can work well with renewable energy systems such as solar thermal panels, further reducing energy bills and environmental impact.

A key advantage of a system boiler is its built-in components. Since the pump and expansion vessel are incorporated within the unit, installation is often more straightforward and quicker than a conventional boiler. The compact design also frees up space in your home by eliminating the need for a separate cold water tank in the loft.

However, there are some disadvantages to consider. The most significant downside of a system boiler is that it requires a hot water cylinder, which takes up storage space within the property. This may not be an issue for some homeowners, but it's essential to consider the available space when making your decision.

As with all types of boilers, regular maintenance is crucial for the longevity and efficiency of the system. Potential issues may arise if the hot water cylinder or pump fails, while the flow rate could be affected if sludge accumulates in the system. Regular servicing by a professional is essential to prevent these issues and ensure optimal performance.

In summary, a system boiler is a great choice for those with larger homes or higher hot water demands. The separate hot water tank and built-in components make for easier installation and efficient operation. However, the space required for a hot water cylinder may be a drawback for smaller properties. When choosing the right boiler, considering how well it suits your needs and available space is essential.

Heat only Boilers

Heat only boilers, also known as conventional or regular boilers, are a type of boiler that works with a hot water cylinder in the airing cupboard, on either an open-vented or closed-vent system. These boilers are connected to both a hot water storage cylinder and a cold water tank, commonly found in the loft. They require expansion tanks to manage excess pressure, and the closed vent system is designed to maintain a steady water pressure in your home.

The pros and cons of Heat Only boilers


  • Hot water on demand: With a heat only boiler, hot water is generated and stored in the storage cylinder, ensuring a constant supply of hot water is readily available when needed.

  • Multiple taps and showers: These boilers can handle running hot water through multiple taps and showers simultaneously, making them suitable for larger households.

  • Compatible with older installations: Conventional boilers are a good option for properties with older radiators and pipework, since they operate at higher pressures.


  • Space requirements: Heat only boilers require a hot water storage cylinder, a cold water tank, and potentially expansion tanks, which can take up significant space in your home.

  • Manual control: Unlike combi boilers, heat only boilers may require manual intervention to set the desired hot water temperature.

  • Slower heat-up time: Due to the need for storing hot water in the cylinder, it might take longer to heat up the water when compared to combi boilers.

When considering a heat only boiler, it's essential to weigh up the pros and cons to determine whether it’s the right choice for your needs. These boilers can offer excellent performance and reliability, particularly in larger homes with multiple hot water outlets and older installations, but they do require more space for installation and may have slower heat-up times than other boiler types.

Electric Boilers

The Pros and Cons of an Electric Boiler

Electric boilers are becoming increasingly popular as an alternative to traditional gas boilers. They offer a number of benefits, making them an attractive option for many homeowners. However, as with any technology, there are also some drawbacks to consider.

One of the main advantages of electric boilers is their energy efficiency. Utilising electricity as a fuel source, they convert nearly all of the energy used into heat. In contrast, gas boilers tend to be less efficient, with some energy lost in the form of waste gases. This means electric boilers can be a more environmentally friendly choice, potentially reducing your carbon footprint.

Another positive aspect of electric boilers is their compact size. Due to their design, they require less space compared to a gas boiler, making them a great choice for homes with limited space. Additionally, installation for electric boilers is generally simpler, as they don't need a flue or gas supply, which can save time and money.

However, it's essential to consider the potential downsides of electric boilers, too. One of the main drawbacks is their higher running costs. Owing to the fact that electricity prices are often higher than gas, you may find your energy bills increase if you opt for an electric system. This might be a significant consideration for budget-conscious households.

Another limitation of electric boilers is their typically lower output. Most electric boilers have a maximum output of around 15 kW, which may not be sufficient for larger homes with multiple radiators and bathrooms. In these cases, it's important to carefully calculate the boiler size you need, taking into account factors such as your home's layout and the number of radiators.

Despite some shortcomings, electric boilers are undeniably a viable option for many homeowners. Their energy efficiency and compact design make them ideal for smaller households and those focused on environmental impact. However, be mindful of higher running costs and the need for an appropriately sized boiler to suit your home's needs while weighing your boiler options.

Boiler Efficiency and Environment Impact

Efficiency plays a crucial role in selecting the right boiler for your home. Not only does energy efficiency save you money on your energy bills, but it also helps reduce carbon emissions, contributing to the fight against climate change.

Condensing boilers are known for their superior energy efficiency in comparison to non-condensing types. These boilers utilise excess heat that would typically be emitted into the atmosphere, resulting in less wasteful energy use and lower CO2 emissions.

However, condensing boilers come with more moving parts, which may lead to slightly higher maintenance costs. Regardless, their overall advantages in terms of efficiency and environmental impact often outweigh any potential downsides.

It's essential to consider Annual Fuel Utilisation Efficiency (AFUE) when assessing a boiler's efficiency rating. This percentage indicates the overall efficiency of a boiler, accounting for the energy consumption and environmental impact.

In addition to boiler type, it's important to consider renewable energy in the context of heating your home. Biomass boilers that burn wood are an environmentally friendly option, as they utilise a renewable energy source. These boilers tend to be larger and require more space, as they are often situated outdoors.

Lastly, energy efficiency doesn't end with your boiler. Your home's insulation quality can affect how well heat is retained, meaning that a well-insulated home will make even an efficient boiler work more effectively. In turn, it reduces energy consumption and overall carbon emissions further.

To sum up, it's important to balance factors such as boiler efficiency, environmental impact, and home insulation when selecting the best boiler for your needs. By doing so, you can lower your energy bills, reduce your carbon footprint, and create a comfortable living environment.

Sizing and Installation Considerations

Determining the right boiler for your property involves considering several factors, including the size and type of your house as well as your existing heating system. Understanding the specific heating needs of your home is crucial for ensuring efficient and cost-effective heating.

When examining the boiler size, it's essential to factor in the number of bathrooms and radiators within your property. The more bathrooms and radiators you have, the greater the boiler size you'll require to meet the heating demands. Additionally, take note that bathtubs and showers may have differing boiler size requirements.

When estimating the boiler size, it's also important to consider your property's insulation levels. Proper insulation is key to efficient heating, so if your house is particularly well-insulated, it may allow you to opt for a smaller boiler capacity.

The boiler installation process comprises another vital aspect to consider. Hiring a professional boiler installer will ensure that your new boiler is fitted correctly, potentially lasting up to fifteen years without issue. However, installation costs might impact the overall boiler cost, so make sure to factor that into your planning.

You should also take into account the compatibility of your new boiler with your property's existing heating system. To maximise efficiency and minimise disruption, it's advisable to choose a boiler that seamlessly integrates with the existing setup.

In summary, determining the right boiler for your property depends on several factors, such as boiler size, heating needs, installation costs, and compatibility with your existing system. Careful consideration in these areas will ultimately result in an efficient, cost-effective, and manageable heating system.

Type of Boiler Based on Your Home

Choosing the right boiler for your home largely depends on the size and type of your property, focusing primarily on the number of bedrooms and bathrooms. Here, we look at suitable options for different types of houses.

For a four-bedroom house, a boiler with a higher heat output is typically needed to meet the demands of providing both central heating and hot water. You may want to consider a system boiler or a conventional boiler, as both can cope well with larger homes. System boilers are efficient and often cost-effective, whereas conventional boilers can handle varying water pressures, making them suitable for older heating systems.

In contrast, a three-bed semi-detached house may require a more compact and efficient boiler. A combi boiler is an excellent choice for this sort of property since it delivers hot water instantly without the need for a separate hot water tank. These boilers save on space and are usually ideal for small to medium-sized homes.

For a three-bed terraced house, a combi boiler or system boiler would both be a good choice, taking into account the number of bathrooms and hot water requirements. Assess the space available for the boiler and any tanks to make a well-informed decision.

In summary, remember to tailor your choice of boiler to the unique needs of your property, accounting for the number of bedrooms and bathrooms, as well as the size and layout of your home. Doing so ensures your home remains warm and comfortable all year round.

Best Boiler Brands

When selecting a new boiler for your home, choosing from the top boiler brands is essential to ensure reliable service and satisfied heating engineers. The market offers a wide variety of boiler brands, each with its qualities and expertise in providing efficient heating solutions. Here, we'll discuss some of the most reputable boiler brands that you can trust for exceptional performance.

Viessmann is a well-established German brand known for its high-quality, energy-efficient boilers. Offering a comprehensive range of gas and oil-fired boilers, Viessmann appeals to customers who seek maximum efficiency and long-lasting performance. Their expertise in advanced heating technology ensures that your investment in a Viessmann model will meet your heating requirements.

Another reputable brand to consider is Worcester Bosch. This UK-based company has built a solid reputation among heating engineers. Known for their efficiency and reliability, Worcester Bosch boilers are widely recommended. Offering an excellent range of gas and oil boilers, the brand caters to various household requirements. Additionally, their exceptional after-sales service sets them apart in the industry.

Ideal Boilers is a proud British brand that has been providing heating solutions for over a century. Their wide range of combi, heat-only and system boilers makes them a go-to choice for versatile and reliable options. Ideal Boilers is perfect for homeowners who prioritise efficiency and easy access to replacement parts.

Next up is Vaillant—another German brand renowned for its innovation and eco-friendly products. With a broad range of reliable heating systems and excellent after-sales support, Vaillant has earned its reputation as a heating industry leader. Their continuous investment in research and development ensures that buying a Vaillant boiler is an excellent choice for efficiency and sustainability.

Last but not least, Baxi has been keeping British homes warm since 1866. Known for their sturdy build and ease of use, Baxi boilers are a popular choice among homeowners and heating engineers. They offer a broad selection of gas boilers, ensuring you find the right model to suit your needs. Baxi's commitment to customer satisfaction makes them a reliable brand for your new boiler investment.

In conclusion, these boiler brands embody quality, reliability and exceptional service. By considering these top choices when buying the best boiler for your home, you can trust that you'll have a dependable and efficient heating solution for years to come.

Remember that the choice of a boiler is ultimately subjective, and it depends on your individual requirements and preferences. However, selecting from these reputable brands is an excellent starting point in your journey to finding the perfect boiler for your home.

New Boiler Costs

Boilers can be a daunting purchase for many people as they’re an appliance with a lot of responsibility, providing heat for you and your family is something you want to get right. Boilers aren’t exactly a quickly disposable item either, potentially lasting you a decade.

Boiler costs can be split into two segments: the first is the actual boiler itself (unit price), and the second is the cost of the boiler being installed (set up) in your property by an expert engineer. 

Here at iHeat, we want to remove all of this undue stress and make the decision making process of upgrading to a new central heating system, as easy as possible.

Boiler costs can vary depending on a number of factors including their brand, model, fuel, output, warranty, labour and installation type. Typically a new boiler will cost between £1,845 and £3,500, below is a list of average boiler installations offered by iHeat.

Installation Type

Price (inc VAT)

Combi to combi swap


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System to combi conversion


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New boiler install


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Back boiler to a combi


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System to system


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Some location factors that can influence the price of your new boiler

You will be given a specific quote from the boiler installation company based on:

  • The type of home you have (i.e. terraced, semi-detached, etc.)

  • How many bedrooms you have

  • How many bathrooms you have

  • Your postcode and specific location

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Frequently Asked Questions

What type of boiler is right for me?

Your ideal boiler type depends on factors like the size of your property, your hot water requirements, and available space. Combi boilers are best for smaller properties without large hot water demands. System boilers are more suitable for homes with multiple bathrooms and consistent hot water needs. Larger homes benefit from heat-only boilers due to their higher hot water capacity.

What are the 3 types of boilers?

The three primary boiler types are combi, system, and heat-only. Combi boilers are compact units that provide on-demand hot water without needing storage tanks. System boilers work in tandem with a hot water cylinder, while heat-only boilers utilise both a cylinder and a separate cold water tank.

What is the most efficient type of boiler?

Condensing boilers are the most energy-efficient as they capture and reuse excess heat that would otherwise be lost. This technology is present in both combi and system boilers. By optimising heat retention, condensing boilers reduce energy consumption and lower heating costs.

What are the 2 types of boiler?

The two main categories of boilers are water-tube and fire-tube. Water-tube boilers circulate water in tubes exposed to the source of heat, while fire-tube boilers pass hot gases through tubes immersed in water. In domestic settings, combi, system, and heat-only are the classifications commonly used.

What is the most common boiler type in the UK?

In the UK, combi boilers are the predominant type. Their compactness, efficiency in delivering on-demand hot water, and absence of a need for storage tanks make them a popular choice for many British households, especially those with space constraints.

What is the most common boiler in the UK?

The combi boiler holds the title for being the most prevalent in the UK. Its design allows for on-the-spot water heating, eliminating the requirement for tanks or cylinders. Its efficiency and space-saving characteristics have made it a favourite among UK homeowners.

What is the most popular type of boiler?

Combi boilers are the most favoured boiler type, especially in the UK. They offer on-demand hot water without the need for storage solutions, making them a top choice for homes with limited space or those seeking efficient heating solutions.

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Article by
Stephen Day | Co-founder
Gas Safe registered and FGAS certified engineer with over 20 years experience in the heating and cooling industry.