Boiler Buying Guide | Types of Boiler Explained | Toolstation

Boiler Buying Guide

Boiler Buying Guide

Heating a home is expensive – and the cost is only set to grow more over the coming year. Upgrading your boiler can have the potential to save lots of money each year if used correctly for even the smallest houses, so it could be worth the investment.

At Toolstation, you’ll find Combination (Combi), System, and Heat-Only boilers, which can be powered with gas, electricity, or liquid petroleum gas (LPG). The right boiler for you will depend on a range of factors, including the size of the building, the space available for a heating system, the number of bathrooms you have, the mains water pressure, and even the type of boiler you already use.

When you’re buying a boiler, make sure you get it properly installed by a qualified tradesperson – such as a Gas Safe Engineer.

Types of Boilers

Combi Boiler
Heat-Only Boiler
System Boiler

Boiler Fuel Types Explained

Boiler Features

Smart Heating

Smart heating controls allow you to control your energy usage from your phone, tablet, or computer so you don’t waste money heating empty rooms. This can save you hundreds of pounds each year on your energy bill.

A boiler can become ‘smart’ by linking it up to a smart thermostat, which allows you to control the heating in each individual room. Smart “learning” thermostats also figure out your daily routine and heating requirements and turn on your radiators when it thinks you’ll need it, so it becomes even easier to manage your energy use.

Most boilers can be made ‘smart’, including combi, system and heat-only models. However, check with the boiler manufacturer before investing in smart heating.

Boiler Size

When talking about the size of a boiler, it generally means the boiler’s kWh capabilities rather than its physical size.

When you’re thinking about the size of the boiler you need, most people consider the number of radiators you have as a guide. For example, if you want a combi boiler and have 10 radiators in your home, you’ll need a 24-27 kWh boiler. However, if you’re using a heat-only or system boiler, you’ll want a 12-15 kWh model.

For combi boilers powering 10 to 15 radiators, you’ll want a 28 – 34 kWh model, but for heat-only and system boilers, you’ll want a 18 – 24 kWh boiler. If you have 15 to 20 radiators, you need a 30 – 40 kWh combi boiler, or a 32 – 40 kWh heat-only or system boiler.

Energy Rating

With energy costs rising rapidly, energy classification has become more and more important. Large appliances, including boilers, are given a rating from A to G, depending on how energy efficient they are. This way we can reduce the energy we waste and use more of it to efficiently heat our homes and offices.

All modern condensing gas boilers will be at least 90% efficient, which gives them an A rating – the highest energy rating an appliance can get. However, older non-condensing models (which are no longer sold) could be as low as 60%, which gives them the lowest energy rating of G.

If you’re still using an old non-condensing gas boiler, you’ll notice a big difference in the cost per year if you upgrade to a modern alternative – and you’ll reduce your carbon footprint!

Hydrogen Ready

As the UK makes an effort to be carbon neutral by 2050, the gas supply will be 100% hydrogen rather than fossil fuels before 2030. As a fuel, the only emissions hydrogen emits is water – making it very clean and environmentally friendly.

At Toolstation, you’ll find 20% hydrogen-blend ready gas boilers. These are prepared to use a 20% blend of hydrogen and 80% fossil fuels from as early as 2023, when the UK government hopes to begin reducing the reliance on fossil fuels.

Manufacturers are committing to keeping hydrogen boilers and hydrogen-blend ready boilers at a similar cost to standard gas boilers, so it’s a good idea to look out for these models if you’re looking to upgrade yours.

Condensing vs. Non-Condensing

A condensing boiler features an element that captures excess energy that would have otherwise been lost, by condensing water vapour within the boiler unit. Non-condensing boilers are older and don’t have this money and energy-saving feature. All boilers sold nowadays are condensing boilers in line with the law. These are at least 90% energy efficient, compared to old non-condensing models which could be as low as 60% efficient.

Upgrading your boiler from an old non-condensing one to a condensing model is not only better for the environment, but can harness extra energy to heat your home or office and reduce your energy bills significantly.

If you’re still using an old boiler, the investment in a new condensing unit will be well worth it when you can save up to hundreds of pounds each year on your energy bills, as well as reduce your carbon footprint.

Frequently Asked Questions

  • What is a combi boiler and how does it work?

    A combi boiler is a single unit and doesn’t need a hot or cold water tank. They provide on-demand hot water for taps and showers, as well as central heating. They work by taking cold water from the mains supply and heating it within the boiler by burning fossil fuels – most commonly gas.

  • How much does a new boiler cost?

    You’ll find new boilers ranging from just £500 up to £1700. If you’re a homeowner, you also need to consider the cost of installation – as you’ll need a Gas Safe Engineer to install your new boiler.

  • What type of shower can you have with a combi boiler?

    If you have a combi boiler, you can have a mixer shower, digital shower or electric shower. Power showers are designed for low water pressure areas, meaning they’re not suitable for combi boilers which rely on a consistent pressure.

  • How do you install a boiler?

    To install a boiler, you need a Gas Safe Engineer. Installation is much simpler if you’re getting a boiler of the same type, and if you’re keeping it in the same place.

  • What is the best combi boiler?

    The best combi boiler is one which is the right size for your building. If you’re living in a two bedroom terraced house, there’s no need to get a 35 kWh model as it’ll be too powerful for your needs and a waste of money and energy. Similarly, if you live in a larger 4 bed, or are heating an office, a 24 kWh combi boiler won’t be up to the task.

  • What is a biomass boiler?

    A biomass boiler works similarly to a standard boiler – simply burning fuel to create energy. However, instead of using fossil fuels, they use sustainably sourced wood pellets. They’re carbon neutral as long as enough trees are planted, as the carbon emitted was actually absorbed by the tree when it was growing.

  • What is the best type of central heating boiler?

    The best type of central heating boiler depends on your needs. If you’re in a smaller house or flat, the best option is probably a gas combi boiler as they’ll have the right amount of power and won’t use up much space. However, if you’re in a larger house and use more hot water at the same time then you’ll want to consider a system boiler or heat–only boiler which can keep up with your requirements.

  • What is a condensing boiler and how does it work?

    Condensing boilers recover water vapour in the exhaust gases and condenses it to gather excess energy created that would otherwise be lost.

  • What is a boiler flue?

    A boiler flue is essentially a tube that allows gas to safely escape a boiler. You can usually spot a boiler flue on the roof or side of a house.

  • Who qualifies for a free boiler grant?

    To get a free boiler, you must either: own your home, live in a council house with an EPC rating of E, F, or G, or live in private rented accommodation with permission from the landlord. In addition, you need to be in receipt of any of the following: child tax credits, working tax credits, income-related ESA, income-related JSA, income support, universal tax credits, or pension credits.

  • What are the different types of boiler systems?

    There are three main types of boiler: combi boilers, system boilers, and heat-only boilers. If you’re looking for an alternative, you can also consider heat pumps or biomass boilers – which the government is currently offering hefty discounts for via the Boiler Upgrade Scheme.

  • How much is an annual boiler service?

    On average, a boiler service costs about £80 – £100.

  • How long does a boiler last?

    The life expectancy of a typical boiler is around 10 and 15 years, but some can last much longer. You should make sure you keep your boiler maintained with an annual service.

  • What is the optimum temperature to set a combi boiler?

    The optimum temperature for a combi boiler is between 50 and 60 degrees celsius. Any lower and the risk of legionella disease increases. Much higher and the efficiency is reduced, but going up to 65 degrees celsius is okay if you like it warmer.

  • What is a heat-only boiler?

    A heat-only boiler, also known as a regular boiler, is the oldest type of boiler and is made up of three parts: the boiler unit, a cold tank, and a hot tank. The cold tank is filled with water from the mains, is heated by the boiler unit and stored in the hot tank, and is then available on demand.

  • How does a boiler heat water?

    Most domestic boilers are gas boilers. A valve allows gas to enter the boiler and is lit in a sealed chamber – which water then passes over to be heated. This will change slightly depending on the type of boiler, but the general process is similar.

  • What is a system boiler and how does a system boiler work?

    A system boiler has a boiler unit and a hot tank. Water is taken from the mains, heated within the boiler unit, and then stored in the hot tank for hot water and central heating on demand.

  • How efficient is my boiler?

    If you have a condensing boiler, it will be at least 90% efficient meaning it has an energy class of A. Old non-condensing boilers may be as low as 60% efficient, so 40% of the energy created is wasted.

  • How do you get a boiler certificate?

    You can get a boiler gas safety certificate when you get your boiler installed by a Gas Safe Engineer and each time you have your boiler serviced, which should be every 12 months. It isn’t a legal requirement for your engineer to give you a boiler certificate, but can be beneficial for your records so you know what work has been done and when.

  • What is the most energy efficient boiler?

    The most energy efficient boiler is the one that’s right for you and your needs. If you buy a pricier boiler designed for a 4-bedroom house but you live in a 2 bed flat, you’ll be wasting energy because it’ll be too powerful.

    Similarly, your boiler will have to work much harder if you buy a lower cost model that can’t keep up with your heating demands.

  • What size boiler do I need?

    If you have 10 radiators, you’ll want a combi boiler around 24 to 27 kWh, or a heat-only or system boiler at around 12 to 15 kWh.

    If you have 15 to 20 radiators, you’ll want a 28 to 34 kWh combi model, or an 18 to 24 kWh heat-only or system boiler.

    For larger properties with 15 to 20 radiators, choose a 32 to 40 kWh combi boiler or a 30 to 40 kWh heat-only or system model.

  • What is the alternative to a gas boiler?

    Not all boilers are gas – alternatives to gas boilers include electric, LPG (liquefied petroleum gas), or oil boilers. Alternatively, you can use a heat pump or a biomass boiler, the latter of which uses sustainably sourced wood pellets.

Hey, browse our site often?