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Last updated: 23rd April, 2024


How To Choose The Right Boiler For Your Home

How To Choose The Right Boiler For Your Home

Key takeaways

  • Understand the different types of boilers to make an informed decision.
  • Consider factors such as budget, efficiency, and modern features while selecting a boiler.
  • Energy-efficient models can provide long-term savings on heating and hot water bills.

Choosing the right boiler for your home can be a stressful and overwhelming experience, but iHeat, an online boiler installation company, makes the process easy and stress-free. Our guide explores the benefits of using iHeat for your boiler installation, including their online quote system, expert advice, and high-quality installation services.

Selecting a boiler for your home can seem like a daunting task, but with the right knowledge and guidance, it doesn't have to be stressful. 

Boilers play a crucial role in providing hot water and heating for your home, so it's essential to make an informed decision to ensure long-term comfort and energy efficiency. 

In this article, we will walk you through the basics of boiler selection, factors to consider, and modern features and technologies to make your choice stress-free.

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When beginning the process of choosing a boiler, it's helpful to familiarise yourself with the different types of boilers available on the market. 

Combi boilers, for example, are popular in Britain due to their compact size and quick installation. 

Meanwhile, system boilers may offer more flexibility in terms of water storage and usage. By understanding the strengths and weaknesses of different boiler types, you can better determine which one will meet your household's needs most effectively.

Budgeting for your new boiler is another significant aspect to consider, as prices can range from £1,000 to £7,000 depending on the model and installation work needed. To ensure that your investment is worthwhile, look into energy-efficient models with condensing technology, such as those from Worcester Bosch. 

These boilers recover heat energy from waste gases, resulting in higher efficiency rates and ultimately decreasing your energy bills in the long run.

Basics of Boiler Selection

Understanding Boilers

Selecting a boiler can be a complicated task, but understanding the fundamentals will ease the process. Boilers are essential components in heating systems, providing hot water and steam for various applications. Their primary function is to transfer heat from a fuel source, such as gas, oil, or electricity, to water, producing steam or hot water as required. When choosing a boiler, it is crucial to take into consideration its capacity, design, fuel type, and efficiency, ensuring a suitable and reliable heating solution for your specific needs.

A vital aspect of boiler selection is determining the correct capacity. Boilers come in various sizes, and selecting one with the appropriate power output will ensure optimal performance. Take the building's size, energy requirements, and insulation into account when calculating boiler capacity.

Types of Boilers (combi/Heat-only/system)

Boilers can be broadly classified into three main categories:

  1. Combi Boilers: Combining both central heating and hot water supply within a single unit, combi boilers offer a space-saving and efficient solution. They provide instant hot water directly from the mains, which means no need for a separate hot water cylinder. Combi boilers are suitable for small to medium-sized homes with limited space.

  2. Heat-only Boilers: Also known as regular or conventional boilers, heat-only boilers operate with a separate hot water cylinder, usually located in an airing cupboard. These boilers require a cold-water storage tank, which can be found in the loft. Heat-only boilers are ideal for larger homes with multiple bathrooms, as they can supply hot water to numerous outlets simultaneously.

  3. System Boilers: A hybrid between combi and heat-only boilers, system boilers provide central heating and hot water supply through a hot water cylinder but do not require a separate cold-water tank. They are more straightforward to install and maintain, making them suitable for medium to large-sized homes requiring a higher hot water demand.

Fuel types for boilers include natural gas, LPG, oil, and electricity. Gas boilers are the most common, as they are both efficient and cost-effective. LPG and oil boilers are alternatives for homes not connected to the gas network, while electric boilers provide a greener and more environmentally friendly heating option.

In summary, when selecting a boiler, consider factors such as boiler design, capacity, fuel type, and efficiency. 

A suitable boiler will depend on your home's size, hot water needs, and available space. By understanding the basics of boilers and the different types available, choosing a stress-free boiler solution is achievable.

Factors to Consider When Choosing a Boiler

Size and Performance

When selecting a boiler, it is essential to consider its size and performance. Boiler capacity should correspond with the size of your property and your hot water demand. Large households with high hot water usage may benefit from a system boiler, whereas smaller homes with less demand may find a combi boiler to be more suitable.

Evaluate your current boiler's performance and identify areas for improvement. Optimal boiler performance depends on the maximum heat absorbed and minimum heat loss. The boiler design should also be evaluated according to its capacity to meet your specific requirements.

Fuel and Efficiency

The fuel type and efficiency play a crucial role in choosing the right boiler. Common fuels include natural gas, LPG, oil, and biomass. Consider the availability of the fuel in your area, as well as the associated costs and carbon emissions.

Boiler efficiency is essential, as more efficient boilers save energy, money, and contribute to a lower carbon footprint. Look for boilers with high efficiency ratings, considering factors like heat loss and flue gases. Additionally, integrating solar water heating or an economiser could enhance the efficiency of your boiler system.

Material and Construction

Select a boiler with durable materials and robust construction to ensure longevity and reliability. Pay attention to the expansion vessel and the type of heat exchanger used in the unit. In addition, proper installation and regular maintenance are vital to maintaining your boiler's performance and prolonging its lifespan.

Safety and Specifications

Safety features and specifications are imperative when choosing a boiler. Ensure that the boiler adheres to relevant safety standards and regulations. Consider factors such as mains pressure and any additional safety mechanisms like pressure relief valves or carbon monoxide detectors.

Furthermore, assess the compatibility of the boiler with your existing heating system or any planned upgrades. This includes evaluating the integration of smart thermostats or other technological enhancements to improve the system's overall performance and user-friendliness.

In conclusion, when choosing a boiler, consider factors like size, performance, fuel, efficiency, material and construction, as well as safety specifications. Utilise this information to make an informed decision for your home, taking into account your specific needs and preferences.

Budgeting for Your Boiler

iHeat 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


Get a quote

System to combi conversion


Get a quote

New boiler install


Get a quote

Back boiler to a combi


Get a quote

System to system


Get a quote

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

Warranties and Guarantees

Another aspect to factor into your budget is the warranties and guarantees offered by manufacturers. Investing in a boiler with a good warranty can save you money in the long run by covering potential repairs or replacements. A longer warranty generally indicates the manufacturer's confidence in their product, thus ensuring peace of mind for you. 

When comparing boilers, also note if they come with guarantees such as satisfaction guarantees, money-back promises, or performance pledges to protect your investment. By taking all these factors into account, you'll be well-equipped to budget for your new stress-free boiler.

Installation and Maintenance

iHeat Engineers

Selecting the right boiler is essential, but equally important is the installation process. To ensure a stress-free experience, iHeat Engineers can provide support during installation. These engineers are Gas Safe registered, which means that they have the necessary qualifications and expertise to handle gas appliances safely.

To get started with an iHeat Engineer, simply request a quote for the boiler installation. Once you have compared and chosen the best option, schedule an appointment for the installation.

Ongoing Maintenance and Checks

Regular maintenance and checks, also called a boiler service, are vital for the longevity and proper functioning of your boiler. A qualified heating engineer should carry out routine servicing at least once a year. This helps prevent breakdowns and keeps your boiler running efficiently.

Some key aspects of ongoing maintenance and checks include:

  • Visual inspection: Examine the boiler and its components for any signs of damage, wear, or corrosion.

  • Cleaning and repairs: Clean the boiler's heat exchanger, burner, and other internal parts. Repair or replace any faulty components.

  • Safety checks: Ensure proper ventilation and make sure all safety devices, like pressure relief valves and thermostats, are working correctly.

In summary, a stress-free boiler selection process involves not only choosing the right boiler but also ensuring proper installation and regular maintenance by qualified professionals. With the help of iHeat Engineers and a strong focus on ongoing maintenance, you can enjoy a warm and comfortable home without worry.

Modern Features and Technologies

Incorporating Smart Thermostats

In today's world, smart thermostats play a significant role in central heating systems. By giving homeowners more refined heating controls, these devices contribute to enhanced comfort and energy efficiency. Smart thermostats allow for remote control and scheduling, ensuring that the heating system operates only when necessary, reducing energy wastage. 

Furthermore, they can learn from homeowners' behaviours and preferences, optimising the system's performance and adapting to their specific needs. Adding a chemical inhibitor to the central heating system can also prolong the efficiency and longevity of the boiler by preventing corrosion within the system.

Condensing Boilers

Condensing boilers are among the paramount innovations in modern boiler systems. These boilers recover heat that would otherwise be lost in conventional non-condensing boilers, resulting in higher energy efficiency and reduced energy bills. 

Condensing boilers minimise environmental impact and ensure compliance with emissions standards by releasing significantly less carbon dioxide and nitrogen oxide compared to older models. They are also compatible with various forms of alarms, such as carbon monoxide detectors, guaranteeing safety and peace of mind.

In essence, when selecting a stress-free boiler, prioritising modern features and technologies, such as smart thermostats and condensing boilers, is vital. Integrating these advanced options will not only improve overall comfort and convenience but also help to maintain energy efficiency and safety within the home.

Environmental Impact of Boilers

Minimising Environmental Impact through Boiler Choices

Boilers significantly influence our carbon emissions. As the emphasis on curbing climate change intensifies, it's pivotal to choose boilers with minimal environmental repercussions. Notably, condensing boilers demonstrate superior eco-friendliness compared to their conventional counterparts, primarily during their usage phase.

Incorporating renewable energy-powered boilers, like those using biomass, is another method to slash carbon emissions. While they do use electricity and generate ash waste, their overall ecological impact is notably lower than that of boilers relying on fossil fuels. To be on track for a mid-century net-zero emissions target, it's advisable to halt new gas boiler.

Choosing a Boiler for Different Properties

Selecting the perfect boiler for your home depends on various factors, including the property size, material, and your specific heating and hot water requirements. A careful consideration of these aspects will ensure optimal performance, energy savings, and long-term peace of mind.

The type of boiler selected should ideally match the size and nature of the property. For instance, combi boilers are most suited to small flats or houses with low water demands, such as one bathroom. They provide hot water on-demand and save space as they don't need a separate hot water storage cylinder.

On the other hand, system boilers are better suited for larger properties with multiple bathrooms or a high hot water demand. These boilers are equipped with an expansion vessel and a circulating pump, which eliminate the need for a loft tank. The main advantage is that they can provide hot water to multiple outlets simultaneously and are usually more energy-efficient.

When it comes to the material of the property, consider that older, less insulated homes may require a more powerful boiler than newer, well-insulated properties. A qualified local engineer can help determine the appropriate size and performance of the boiler you'll need based on the property construction and insulation levels.

Energy savings should also be considered when selecting a boiler. Choose a boiler that offers high efficiency and is compatible with smart thermostats for better control over your central heating. This will not only lead to reduced energy consumption but also contribute to lower utility bills and a smaller carbon footprint.

Finally, consult a professional local engineer who can provide recommendations tailored to your specific requirements. They can assess your home's heating needs, suggest suitable boiler models, and arrange for the installation of your new system, ensuring your central heating system operates with utmost efficiency and reliability.

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Frequently Asked Questions

How do I choose a boiler?

To choose a boiler, consider factors such as the type of fuel it uses, its energy efficiency, installation cost, and the size of your home. For most UK homes, a gas-powered combi boiler is a popular choice, as it combines a water heater and central heating system in one package.

How do I calculate what size boiler I need?

Calculating the right boiler size depends on your property's heating requirements. This typically considers factors such as insulation, square footage, and the number of radiators. It's generally best to consult a qualified heating professional who can accurately assess your specific needs.

Is it better to get a higher kW boiler?

Higher kW boilers can provide greater heat output, but they may not always be necessary. In some cases, a larger boiler can result in wastage of energy. It's important to accurately determine the kW needs of your home before selecting a boiler.

How many kW boiler do I need for a 4 bed house?

The kW requirement for a 4-bed house depends on factors like insulation, square footage, and the number of radiators. On average, a 4-bed house may need around 24-30 kW for an energy-efficient boiler. A heating expert can provide tailored advice for your property.

Do I need a 25kW or 30kW boiler?

Choosing between a 25kW and 30kW boiler depends on your home's specific heating demands. Factors such as insulation, size, and radiator count will influence your decision. To determine the correct kW boiler for your needs, consult a heating professional.

How big a house will a 30kW boiler heat?

A 30kW boiler can typically heat a larger home, such as a 4-to-5-bed house with multiple bathrooms. However, the heating needs of a home are influenced by several factors, including insulation, size, and the number of radiators. Consulting a heating expert is essential for precise recommendations.

How many radiators can a 24kW boiler run?

The number of radiators a 24kW boiler can run depends on factors like radiator size and energy output. On average, a 24kW boiler can manage around 10 to 15 radiators, but this may vary based on specific requirements. A heating professional can provide a more accurate assessment for your home.

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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.