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Baxi 800 Combi, System & Heat Boiler – Review

Viessmann Vitodens 050-W Gas/LPG Boiler | Boilerhut
Witten by Bernard Morgan (Engineer) & Adam Apperley (Marketing). Published: June 16, 2021. Updated: January 23, 2024

Boiler only price: from £1,270

(18kW system boiler-only price: comparing five or more suppliers, including Screwfix and Plumbase. Correct January 2024).

The Baxi 800 range is a wall-mounted gas condensing boiler.

  • Compact unit that can fit inside a kitchen cupboard.
  • Quiet operation.
  • Open Therm compatible for the best efficiency.
  • Up to 10-year warranty.
  • Available as a combi boiler, system boiler or heat-only boiler.

This boiler is Baxi’s top model.

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  • The Baxi 800 Boiler is a mid-range boiler, making it an appropriate choice for larger homes and apartments.
  • Easy to install in a standard cupboard in a kitchen, bathroom or airing cupboard
  • Can integrate with Baxi’s optional uSense smart thermostat
  • Features a large LED display, extensive flue options up to 20 metres and a brass hydraulics block
  • Offered with a 10-year standard parts and labour warranty.

Models in the Baxi 800 range

  • Combi boilers
    • Baxi 824 Combi 2 – 24kW
    • Baxi 830 Combi 2 – 30.9kW
    • Baxi 836 Combi 2 – 36.9kW
  • System boilers
    • Baxi 818 System 2 – 18kW
    • Baxi 824 System 2 – 24kW
    • Baxi 830 System 2 – 30kW
  • Heat-only/regular boilers
    • Baxi 816 Heat – 16kW
    • Baxi 825 Heat – 25kW
    • Baxi 830 Heat – 30kW

Technical Specification:

Manufacturer Baxi
Model 800
Condensing Yes
Efficiency Rating 93%
Energy Efficiency Class A-Rated
LPG Compatible No
Warranty 10-year warranty
Baxi 800 Combi 2 Model Output: 24kW, 30kW & 36kW

Flow rate: 10.2, 12.2 & 15 litres/minute

Baxi 800 System 2 Model Output:18kW, 24kW & 30kW
Baxi 800 Heat Output:16kW, 25kW & 30kW
Central Heating Max. Output 22 or 28 kW
Mounting Wall Mounted
Weight 30 kg
Dimensions 700 mm (Height) x 390mm (Width) x 285 mm (Depth)

Key Features:

  • Holds an ERP ‘A’ energy efficiency rating, with an operation of 93% efficiency.
  • Available as system, regular (known as ‘heat-only’ in the Baxi range) or combi boiler models:
    • Baxi 800 System 2.
    • Baxi 800 Heat.
    • Baxi 800 Combi 2.
  • Baxi 800 Combi 2 and Baxi 800 System 2 have stainless steel heat exchangers.
  • Compact and lightweight design, making it easy to install.
  • Can be installed in a large cupboard or airing cupboard space because of its small size, or wall-mounted.
  • Simple to use manual control panel.
  • Includes built-in frost thermostat to reduce frost risk, if installed in a non-insulated part of your home.
  • Open Therm compliant for better efficiency and modulation.
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Our thoughts:

The Baxi 800 comes with several useful add-ons and accessories. These include smart controls, a range of flues, plus the Adey Micro2 magnetic system filter. This filter helps to protect the heating system and boiler over its life.

Our engineers don’t install Baxi’s very often, but they are well-liked. They are good solid units with great warranty periods for peace-of-mind.

A global brand

Baxi is well known as a British boiler manufacturer. It is now worldwide due to being owned by The Netherlands based BDR Thermea Group. They own and operate heating companies in over 80 countries. It should be noted, though, that Baxi isn’t considered a premium boiler brand and is more of a middle-of-the-range brand. However, this doesn’t stop them from producing robust and reliable models popular with homeowners.

Great customer service

Baxi has won awards for its customer service. Alongside the extended warranty on this boiler, there are plenty of reasons to relax with a Baxi boiler. For the price you pay for the boiler, the service in this regard is excellent.

Reasonable household energy consumption

Baxi boilers have a 93% energy efficiency A rating. So, like with many modern boilers, upgrading could save you money.

Hot water when you need it

The Baxi 800 Combi 2 model will provide a 10.2 to 15 litre per minute flow rate of hot water. That means you will never have to wait for a shower.

Wide availability of parts 

Baxi has been manufacturing boilers in the UK for over 160 years. Parts are widely available because of the widespread availability of the Baxi boiler range. You can get parts online and in plumbers merchants across the country.

Verdict and Final Thoughts

Overall rating: 7/10

Cost-effectiveness: 8/10

Energy efficiency: 7/10

The Baxi 800 range is a quality mid-range boiler. Whether you are getting the Baxi 800 Combi 2, the 800 System 2 or the 800 Heat they will work hard for you.

They may not have the bells and whistles that a premium brand like Viessmann has, but this boiler is less expensive than the Viessmann top-tier model.

We don’t install many Baxi boilers, this isn’t because we don’t like them, but our customers tend to prefer a different brand. Saying that our engineers have told us:

  • “The 800 Combi 2 is easy to fit and easy to service”
  • “Affordable and does the job well”
  • “The new ones have stainless steel heat exchangers which will help keep them going longer than a lot of premium brands”

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