Baxi 400 Boiler

The Baxi 400 Boiler is a highly functional Baxi boiler range, with three power output versions available – the 400 Combi, 400 Combi LPG and 400 Heat and a range of kW sizes.

Our team has reviewed this model and this review covers everything you need to know before deciding whether it is the right fit for your property and household.

Price (Installed): From £1914 (inc. VAT)

Baxi 400 Boiler Technical Specification

Manufacturer Baxi 
Model 400 Combi, 400 Combi LPG and 400 Heat
Condensing Yes
Efficiency Rating 89%
Energy Efficiency Class A-Rated
LPG Compatible Yes – in the case of the Combi LPG
Warranty 5-year warranty
Central Heating Max. Output 30kW
Mounting Wall Mounted
Weight 19.5 kg (Heat) or 26 kg (Combi and LPG)
Dimensions 400 Heat: 625 mm (Height) x 370 (Width) x 270 mm (Depth)

400 Combi/400 Combi LPG: 700 mm (Height) x 395 (Width) x 279 mm (Depth)

The Baxi 400 Boiler is available as a combi boiler in 24kW and 28kW and as a conventional (400 Heat) boiler in 12kW, 15kW, 18kW, 24kW, 28kW and 30kW. An LPG version is also available in 28kW.

Baxi 400 combi boiler flow rates

kW Size Flow Rate
24kW 11.5 l/min
28kW 13.4 l/min

Baxi 400 Boiler Key Features

  • The Baxi 400 range is available in Combi, Combi LPG and heat-only models
  • 5-year parts and labour warranty
  • Simple to use LCD manual control panel
  • Holds an ‘A’ energy efficiency rating, but with an 89% efficiency rating there are other more efficient boilers available
  • Provides adequate heating and hot water for an average-size home
  • The Baxi 400 Heat is compatible with the Megaflo eco cylinder
  • Quiet running volume
Interested in the Baxi 400 Boiler?

About the Baxi 400 Boiler

The Baxi 400 Boiler is a quiet and compact heating and water system. All of the models in the range will fit into a standard kitchen cupboard. This makes it ideal for those with limited space, but who are looking to install an effective boiler that can heat their home.

The Baxi 400 Heat – which weighs 19.5 kg, is one of the lightest boilers currently available on the market.

  • Can be installed in a standard cupboard in a kitchen, bathroom or airing cupboard
  • Can be integrated with smart thermostats and controls, so that it can be controlled from a mobile phone or tablet wherever you are with an internet connection
  • The Baxi 400 Combi LPG features a rigid filling loop for a neater finish 
  • Comes with a standard 5-year parts and labour warranty

Our thoughts on the Baxi 400 Boiler

The Baxi 400 Boiler is smart-compatible and a relatively new addition to the UK boiler market. It is a lightweight and affordable boiler option, although some customers may be put off by the number of plastic components it contains.

It is easy to install and service, available in multiple heating outputs to accommodate most homes and features an in-built frost thermostat and a choice of different flue lengths.

A trusted brand

Baxi is an international company, with headquarters in The Netherlands, but they have been synonymous with reliable British-manufactured boilers since 1866.

They are particularly popular with landlords who are looking for a reliable, easy to install and quiet boiler option for their rental properties.

Energy-efficient so you reduce your bills

The Baxi 400 has an ErP ‘A’ rating and an energy efficiency running performance of 89%. While there are more efficient boilers out there, for maximum energy efficiency, there is a range of compatible wired and wireless controls available, including the option to connect with a smart energy management system such as the uSense smart room thermostat which can increase energy efficiency within your home. 

By controlling the boiler from your smartphone, computer or tablet you can ensure your heating is managed carefully and you can take advantage of additional features, including temperature scheduling, the ability to input holiday periods, and anti-frost protection.

Easy Installation

Being wall-mounted, and compact and lightweight, all of the Baxi 400 model boilers are popular with installers because they are easy to set up and install. 

Wide availability of parts 

Because they are manufactured in the UK, at plants in Preston and Norwich, parts for the Baxi 400 are widely available. If you need a replacement item you can find spare parts at Screwfix, Plumbase and other plumbing merchants both in-store and online.

Interested in the Baxi 400 Boiler?

How Much are the Monthly Repayments for a Baxi 400 Combi Boiler?

Using our boiler finance calculator, you will be able to see the typical monthly repayments for a Baxi 400 Boiler should you choose to take out a finance plan for this boiler.


Interested in the Baxi 400 Boiler?