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Baxi 800 Combi Boiler


The Baxi 800 combi boiler range is something else. It’s arguably even better than the Baxi 600 combi boilers. As expected of Baxi, they did their best to ensure there is something for everybody.

In this product line, we have the Baxi 825, 830, and 836 combi boilers. Not only do they come with A-rated energy efficiency ratings, but they also have convincing features.

Do you want to figure out which Baxi 800 Combi Boiler is best for your household?

Continue reading to find out more.

Baxi 800 Combi Boiler Key Features

  • They’re all high-end condensing boilers.
  • They all have a minimum efficiency rating of 93%.
  • All of them are ErP A-rated for both central heating and hot water production.
  • Stainless steel heat exchangers.
  • Brass hydraulics blocks.
  • The least has a hot water max output of 25kWs.
  • Can serve a minimum of 10 radiators.
  • The least offers a hot water flow rate of 10.2 litres per minute.
  • They all come with a standard 10-year warranty.
  • They all come with the ADEY Micro2 magnetic system filters that protect the central heating systems from debris buildup.
  • The in-built filling loops make refilling that much easier.
  • They’re all compatible with USense Smart Controls (Boiler Plus compliant).
  • They’re all compatible with the In-Flue Outdoor Sensor (IFOS).
  • All of them offer extensive flue options of up to 20 meters.
  • All Baxi 800 Combi Boilers are compact enough to fit in a standard kitchen cabinet.


As expected of high-end boilers, all Baxi 800 Combi Boilers are premium built.

Indeed, they all come in white and have simple designs. Nonetheless, we appreciate their seamless finish and overall material quality.

First and foremost, we’d like to bring to your attention that all boilers come with stainless steel heat exchangers and brass hydraulics blocks. Unlike other plastic boilers, these will survive the test of time.

Next, we appreciate how Baxi designers tried their best to keep everything neat. The boiler buttons are nicely embedded into the casings. Additionally, there are no pipes within the vicinity. All of them are neatly tucked within the boiler units.

Finally, we have the LCDs for fault code, temperature settings, and status display.

Fuel and efficiency

All Baxi 800 Combi Boilers are certified and endorsed by Energy Saving Trust for their high 93% efficiency ratings. Additionally, they have an ErP A-rating for central heating and hot water production.

Will the Baxi 800 Combi Boilers save you money?

Yes. Since most of the fuel is converted to heat energy, you’ll end up spending less on fuel. Furthermore, they will also reduce your household’s carbon footprint.

Indeed, all of these Baxi boilers run on British Gas. Nonetheless, they’re also certified for a 20% hydrogen blend.

Power output rating

As mentioned earlier, the Baxi 800 range offers a variety of combi boilers, each suiting a specific household.

Remember, you need to size your boiler to avoid purchasing an oversized or undersized boiler.

The Baxi 825 Combi Boiler has a central output rating of 21.2kW and a domestic hot water output rating of 25kW. Therefore, it’s perfect for smaller households with one bathroom and up to 10 radiators. Also, it has a hot water flow rate of 10.2 litres per minute.

For medium-sized households with up to two bathrooms, we recommend the Baxi 830 Combi Boiler. Its central output rating of 21.2kWs and a hot water output rating of 30kWs will suffice. Additionally, its hot water flow rate of 12.2 litres per minute can operate up to 20 radiators.

Finally, we have the Baxi 636 Combi Boiler. It’s the most powerful in the boiler range. With central and hot water output ratings of 26.4kWs and 36kWs, respectively, it can serve larger households with more than two bathrooms. Its hot water flow rate of 15 litres per minute can handle more than 20 radiators.

Installation and servicing

Indeed, all Baxi 800 Combi Boilers are user and installer-friendly. The heaviest weighs 30.5kgs and will require, at most, two engineers to install.

Additionally, they also come with several add-on accessories that will ease the installation process. They include wall-mount brackets and flue options, among others.

Finally, the Easy-Fill lever enables you to re-pressurize your system without calling a professional heating engineer.

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