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Baxi 800 Heat Boiler

The Baxi 800 Heat is a good option for homes with multiple bathrooms and high demand for hot water.

Suitable for open vent and sealed systems, Baxi’s 800 Heat boiler comes in three outputs and is very quiet in operation. It has compact dimensions and can comfortably fit inside a standard kitchen cupboard, enabling you to keep it hidden away. This lightweight heat-only boiler also comes with a generous warranty and is a good option for homes with more than one bathroom and properties in areas with low water pressure. 

How Much Does this Boiler Cost?

Baxi’s 800 Heat is an affordable heat-only boiler available in 16kW, 25kW and 30kW outputs that will set you back anything from £990 to £1,110. The amount you need to spend depends on the boiler size you require, plus you have to add on installation costs. Boiler installation costs vary wildly across the UK, so we recommend you look around and compare prices. If you want to find the best price, you should get a fixed-price quote from local and national installers. 

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

The Baxi 800 Heat is a heat-only boiler, also known as a regular, traditional or open vent boiler, and is ideal if you want to replace an existing heat-only boiler. All heat-only boilers require two water tanks in the loft and a separate hot water storage cylinder, usually located in an airing cupboard. Heat-only boilers are perfect for homes with several bathrooms and high demand for hot water. 

You must select the right boiler type and size for your needs, so be sure to get the unbiased opinion of a Gas Safe registered engineer before making any decisions about the Baxi 800 Heat. 

Is it a High Efficiency Boiler?

It is. The Baxi 800 Heat is a modern boiler with an A energy rating and an efficiency score over 90%. This heat-only boiler is also an Energy Saving Trust endorsed product. 

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

This powerful heat-only boiler from Baxi includes an easy fit wall mounting bracket, a set of easy to use controls, and a compact Adey Magnaclean Micro2 magnetic system filter to protect the heating system. The Baxi 800 Heat works quietly and comes with front and side access to all components to make servicing and maintenance quick and easy. And as there is no requirement for a pump overrun or permanent live, you can expect less disruption and save time and money during installation. 

How long is the Warranty on this Boiler?

If you hire a Gas Safe registered engineer to install the Baxi 800 Heat, you’ll receive a generous 10-year parts and labour warranty.

Summary of Important Information

  • Expect to pay between £990 to £1,110
  • Heating output of 16kW, 25kW or 30kW
  • Dimensions of 625mm (H) x 370mm (W) x 270mm (D)
  • Uses gas as its fuel source
  • A-rated for efficiency
  • 10-year warranty as standard

Pros and Cons

If you’re a busy household, have multiple bathrooms and often run two hot water taps simultaneously, the Baxi 800 Heat will keep up with your demands. It’s a powerful little boiler with an affordable price tag, but remember to consult an engineer to help you work out what output is best suited for your home. 


  • Baxi has a Which? brand score of 76% – correct at the time of writing – January 2022
  • Considerably cheaper than some other boiler brands
  • Fits inside a kitchen cupboard
  • Suited to small, medium and large-sized homes 
  • Easy to install, use and service
  • Industry-leading Adey Magnaclean Micro2 magnetic system filter – protects the boiler and heating system
  • Very quiet in operation – minimal disturbance during use
  • No pump overrun or permanent live required – saves time and money during installation
  • Front and side access to all components – saves time when servicing
  • Compatible with the market-leading Megaflo Eco Cylinder
  • Provides maximum energy efficiency – reduce fuel bills and carbon emissions
  • Energy Saving Trust endorsed product
  • Excellent rating on Trustpilot – correct at the time of writing – January 2022
  • 10-year parts and labour warranty


  • Requires separate cylinder and loft tanks
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