Keston Heat Boiler

The Keston Heat is an efficient boiler that is ideal for larger properties and can be installed in a cascade to produce a higher output.

Powerful enough to cope with high hot water demands, the Keston Heat is a fairly big boiler that provides high efficiencies and is perfect for large homes and light commercial settings. Not only does it come with a wide range of great features but this boiler also meets NOx Class 5 classification, making it an environmentally friendly solution. Not forgetting that up to 6 of these boilers can be installed together to provide a huge maximum output of 330kW.

How Much Does this Boiler Cost?

The Keston Heat is available with an output of 45kW or 55kW, with prices ranging from around £2,350 to £2,700. If you require the higher output, then you can expect to pay the higher price. This does seem quite expensive for a boiler but you need to remember that it comes in unusually high outputs. Something else you need to keep in mind is that these prices do not include the installation cost, so you’ll need to pay extra for the fitting work. 

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How will I know if this Boiler is Suitable for My Home?

Because of the high 45kW and 55kW outputs, this boiler is only suitable for large homes and light commercial properties. If you need a powerful boiler such as this one, you’ll also need space to house a separate water cylinder and water tank. One of the great things about the Keston Heat is that it can be used as part of a cascade system of up to 6 boilers. To create a cascade system, your installer will need to use a special frame and header kits made by Keston.

Before you purchase the Keston Heat or any other boiler, you must ask a Gas Safe registered engineer to help you determine the right size of boiler for your home. If you pick a boiler that is too big and powerful for your property, it will use more fuel and your energy bills will be unnecessarily high. A qualified engineer will take a look at your property and help you find a boiler that is just right for your needs.  

Is it a High Efficiency Boiler?

Regardless of whether you need the 45kW or 55kW Keston Heat, you can be safe in the knowledge that your boiler is A-rated for energy efficiency. The boiler is actually Boiler Plus compliant as standard because it’s fully modulating and has a low energy modulating pump, as well as an inbuilt weather compensator. In addition to being a high efficiency boiler, the Keston Heat achieves low NOx emissions at Class 5 to help you achieve a reduction in your carbon footprint.

Does this Boiler have a Good Range of Controls and Features?

Yes, the Keston Heat comes with a range of excellent features and user-friendly controls. Features include an inbuilt weather compensator, inbuilt low energy modulating pump and a 5:1 turndown ratio. It also has a twin flue of up to 21 metres and a 50mm muPVC solvent weld flue for simple installation. Furthermore, the Keston Heat has commercial control system compatibility as standard and, like we said before, can be installed in a cascade. It’s also worth mentioning that there are LPG variants available and the boiler is ECA listed, which means it meets certain set energy saving criteria.

How long is the Warranty on this Boiler?

Surprisingly, the Keston Heat has only a 2-year parts and labour warranty as standard. You might be able to extend his to 5 years if the boiler is commissioned by Keston Boilers and a 28mm Keston System Filter is installed with the boiler.

Summary of Important Information

  • Priced between £2,350 to £2,700
  • Heating output of 45kW or 55kW
  • Dimensions of 850mm (H) x 500mm (W) x 360mm (D)
  • Uses gas or LPG as its fuel source
  • A-rated for efficiency
  • 2-year warranty as standard

Pros and Cons

Without question, the Keston Heat is a mighty boiler that will satisfy the needs of a large household or small commercial setting, including those with two or more bathrooms. It’s also good to know that there are both natural gas and LPG variants available for those living either on or off the gas network. There is a big con, though. Keston Boilers has a ‘poor’ Trustpilot rating, so it might be wise to speak to some Keston approved engineers for further advice on this prior to purchasing the Keston Heat. 


  • Suited to large homes and light commercial buildings
  • Easy to install, use and service
  • Can be installed in a cascade using Keston frame and header kits
  • Inbuilt low energy modulating pump
  • 5:1 turndown ratio
  • Commercial control system compatibility
  • Weather compensation supplied as standard
  • Provides maximum energy efficiency – reduce fuel bills and carbon emissions
  • Compatible with Keston 28mm System Filter – improves efficiency and performance
  • Works with LPG if required  – perfect for properties off the gas grid
  • ECA listed  


  • Keston has a ‘poor’ Trustpilot rating – correct at the time of writing in May 2019
  • Requires separate tank and cylinder

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