Guide to the best Combi Boilers

Most of us don’t consider our boilers – until they fail. If your boiler is 10 years old or over, then it’s time to think about a replacement. A combination boiler to give it its full name, is the most popular type of boiler in Britain and is installed in homes across the country.

Our guide to the best combi boilers is designed to help you make a decision as to what type of combi is best for your home. There are plenty of benefits to having this type of boiler installed, and a good combi boiler will be energy efficient while warming your home and delivering plenty of piping hot water.

Buying a new boiler can be a minefield. But with the right information at your fingertips, you can make the best choice of new boiler for your home.

What is a combi boiler?

As its name suggests, a combi boiler combines the functions of heating your home and producing hot water. The most common type of combi boilers are gas-fired, but oil-fired and electric-powered boilers also exist.

These highly efficient units are a particularly good choice when space is at a premium because they do away with the need for a hot water storage cylinder. That’s because they heat the water directly from the mains supply via a heat exchanger so it’s always hot when you turn on the tap. And because the water is delivered at mains pressure, you won’t need a shower pump to enjoy a power shower.

Why choose a combi boiler

There are plenty of reasons to choose a combi boiler:

  • If your home doesn’t have the loft space for a separate water tank
  • When you want energy-efficient heating and hot water
  • If you need hot water on demand without having to wait for a tank to heat up
  • If you want a power shower without the expense of fitting a pump system
  • If you don’t have a lot of space in your kitchen and need a space-efficient boiler
  • Combi boilers can be installed quickly and easily, keeping costs low

The benefits of a combi boiler

Combi boilers are ideal for smaller properties and they can free up valuable living space by leaving the loft available for conversion. There’s also no risk of pipework freezing because the installation is self-contained.

Plumbers prefer to install combi boilers because they’re simple and easy to maintain units. That helps to drive down the price of the initial installation and your ongoing running costs. Maintenance is more straightforward as the reliance on mains water means less sludge builds up in the system and water is always safe to drink.

Combi boilers are highly energy efficient which is important when 55 per cent of your energy bill goes on heating your home. Look for a boiler rated A and above for the best performance and you’ll see the difference in your Energy Performance Certificate – a real selling point when you decide to move house.

Is a combi boiler right for my home?

A combi boiler is ideal for a smaller property with only one bathroom. However, it might not be the best choice if:

  • Mains pressure is weak
  • Your house is large with several bathrooms as the water flow will have to be divided, making it weaker
  • You use solar power as an energy source

The best combi boiler for your home

The best combi boiler for your home will be made by a reputable brand and correctly sized for your requirements. Too small and the water flow to taps and radiators will be underwhelming. Too large and you’ll be wasting money and energy.

One of our professional heating engineers will be able to advise you but as a general rule, the larger your home, the more powerful the boiler you’ll need:

  • 1-2 bedroom house or flat with up to 10 radiators: 24-27kW
  • 3-4 bedroom house, 1-2 bathrooms, up to 15 radiators: 28-34kW
  • Large house, 2 bathrooms, up to 20 radiators: 35-42kW

The top combi boiler manufacturers

The single most important factor when choosing a new combi boiler is the brand. An unreliable make can fail early, costing you on average £200 for a boiler repair.

All modern combi boilers are also condensing boilers, giving them an energy efficiency of at least 90 per cent and up to 98 per cent, compared to a standard boiler which is generally 70-80 per cent efficient. But there’s no one size fits all solution.

We’ve installed hundreds of boilers in the Bristol area and we know the importance of boiler reliability. According to a Which? survey, if you choose one of the top three most reliable boilers then they’re 63 per cent more likely to remain fault free after an impressive six and a half years.

With up to a 10-year guarantee available on their boilers, these are the top three brands that we recommend at Ambient Heat:

Worcester Bosch: this German manufacturer enjoys enormous brand loyalty in the UK, with a range of models that are designed to suit any home. Their boilers have been installed in millions of British homes and regularly appear on best buy lists.

Boilers from this company are highly reliable and well made, from the affordable and highly rated Greenstar range to the Classic series that is capable of meeting the heating and hot water needs of larger properties with 2 bathrooms. These boilers are covered by up to a 10-year guarantee and can only be installed by accredited heating engineers for peace of mind.

As the market leader, Worcester Bosch boilers consistently rank highly for customer satisfaction. But that doesn’t mean that they rest on their laurels and they continually innovate to create products that are environmentally friendly and easy to use. These boilers are the smart choice if you’re looking for a user-friendly combi unit with some smart features that protect against damage and reduce energy use.

Vaillant: Another German brand, Vaillant are at the premium end of the spectrum in terms of price but their boilers are packed with innovative technology and high-end components. With over 100 years of experience, Vaillant pioneered the combi boiler.

With up to 10 year guarantees available on their flagship ecoTEC Plus combi boiler range, these A-rated boilers are highly energy-efficient and deliver precision heating and hot water within 5 seconds. Regularly ranked as one of the top 3 combi boiler brands in the UK, Vaillant boilers have a reputation for construction quality and environmental awareness, with low CO2 emissions.

Highly durable, Vaillant combi boilers are suitable for small and medium-sized installations with boiler sizes from 25 to 38kW. If you require a boiler that can cope with higher heating and hot water demands, try the Vaillant EcoTec Exclusive range.

Viessmann: this brand consistently tops the Which? Boiler Best Buy survey with its Vitodens combi boilers sized to suit any home and any budget. One of the quietest boilers available, the Vitodens range are particularly compact and highly efficient up to 98 per cent, thanks to the high specification of their components. Viessman boilers routinely use a stainless steel heat exchanger that is vastly more efficient than the aluminium exchangers used in some other boilers.

The UK’s most efficient boilers, Viessmann focus on future-proofing their products and creating environmentally-friendly units for home use. The decision to use stainless steel ensures that Viessmann boilers are durable and corrosion-resistant for a longer and more energy-efficient lifespan.

Have your new Viessmann, Vaillant or Worcester Bosch combi boiler installed by us and you’ll benefit from a 10-year guarantee on the boiler of your choice.

Getting the best combi boiler installation

Having your boiler professionally installed is critical. A poorly installed product won’t run efficiently and may even fail early. You can avoid wasting money on repairs with a professional installation. Your heating engineer is a mine of useful information about getting the most out of your boiler and will have a good understanding of your heating and hot water requirements.

With two-thirds of gas work found to be unsafe a figure that rises to 75 per cent in London, it’s more important than ever that you have your boiler installation carried out by Gas Safe professionals. At Ambient Heating all our engineers are on the Gas Safe Register to ensure that your new combi boiler is safely installed.