The Baxi 836 Combi 2 is the highest domestic-hot-water-output model in Baxi's current 800 Combi 2 range. It offers strong hot-water performance, but—like other combis—its available flow is shared when several outlets are used at the same time. That makes the incoming mains supply and household hot-water pattern important when deciding whether it is the right fit.
This review covers the current manufacturer specifications, output, flow rate, dimensions, warranty and the practical factors to check before choosing it.
Main Features of the Baxi 836 Combi 2
Current Baxi manufacturer specifications for the 836 Combi 2 include:
- 36kW domestic hot water output
- Up to 27.1kW central-heating output in condensing operation (25kW non-condensing rating)
- 10-year parts and labour warranty, subject to Baxi's registration and servicing terms
- Natural gas operation with manufacturer-specified manual conversion to LPG
- ADEY MagnaClean Micro2 magnetic system filter included
- Compact dimensions: 700mm high × 395mm wide × 285mm deep
It combines good efficiency with a compact design, making it suitable for homes where space is limited.
Baxi 836 Output and Performance
The boiler produces:
- Up to 27.1kW central-heating output in condensing operation (25kW non-condensing rating).
- 36kW domestic-hot-water output, with a manufacturer-stated maximum flow rate of 15 litres per minute at a 35°C temperature rise.
The specification provides strong single-outlet hot-water performance, but suitability still depends on incoming mains flow/pressure and simultaneous demand. Baxi's own guidance notes that combis are particularly straightforward for one-bathroom homes because flow can reduce when several outlets are opened together.
Other Boilers in the Baxi 800 Range
If the 836 offers more hot-water output than you need, the current Baxi 824 Combi 2 or 830 Combi 2 may be more appropriate after a proper sizing assessment.
The 836 has the highest domestic-hot-water output in the current 800 Combi 2 range. Do not select it purely from property size; heat loss, mains performance and hot-water use should be checked first.
Baxi 836 Dimensions
The Baxi 836 measures:
- Height: 700mm
- Width: 395mm
- Depth: 285mm
- Weight: 30.5kg
Its compact size allows it to fit inside many standard kitchen cupboards while remaining straightforward for installers to handle.
Warranty and Aftercare
The current Baxi 836 Combi 2 carries a 10-year parts and labour warranty when the installation meets Baxi's terms and the warranty is registered within 30 days.
Baxi's warranty conditions also require the Benchmark commissioning documentation to be completed, annual servicing by a Gas Safe registered engineer, and the magnetic system filter to be fitted and maintained as required.
Baxi Customer Reviews
As checked on 10 August 2026, Baxi UK's Trustpilot profile showed a 4.6/5 rating from more than 77,000 reviews. This is a company-wide service and brand rating, not a product-specific score, and it changes over time.
Use Trustpilot only as company-level context. Whether the Baxi 836 Combi 2 suits a particular home should be judged from current manufacturer specifications and the property's heating and hot-water requirements.
Is the Baxi 836 Worth Buying?
If you need a combi boiler with strong hot water performance, the Baxi 836 is worth considering. Pros:
- Excellent warranty
- Compact size
- High efficiency
- Natural gas with manufacturer-specified LPG conversion option
- Strong hot water performance
Potential drawbacks:
- Hot-water flow is shared when several outlets are used simultaneously
- Higher output than smaller homes may need
For homes where the calculated heating load and hot-water demand match its specification, the 836 Combi 2 is a strong current option. A one-bathroom property is the more straightforward combi use case; homes with several bathrooms used together may be better served by stored hot water. This page focuses on the Baxi 836 specifically, but if you're comparing different makes and models, our guide to the best combi boilers in the UK can help you weigh up the alternatives before deciding.
Frequently Asked Questions
How many radiators can a Baxi 836 run?Baxi does not publish a fixed radiator count for the 836 Combi 2. Central-heating output should be matched to a room-by-room heat-loss calculation, so do not convert the boiler's maximum kW rating directly into a radiator count.
What is the flow rate?Baxi states a maximum domestic-hot-water flow rate of 15 litres per minute at a 35°C temperature rise.
How long does installation take?A straightforward like-for-like replacement typically takes around one day. Converting from a different system type, or where pipework needs rerouting, can take longer.
What fuel does the Baxi 836 use?The current 836 Combi 2 is supplied for natural gas and can be manually converted to LPG in accordance with Baxi's instructions by a suitably qualified Gas Safe engineer.
Can the Baxi 836 Combi 2 run on LPG?Yes. Baxi lists manual natural-gas-to-LPG conversion for the current 800 Combi 2 range. The conversion is gas work and must be carried out in accordance with the manufacturer's instructions by a suitably qualified Gas Safe engineer.
Looking for a Baxi Boiler Installation?
If you've decided the Baxi 836 is the right choice, choosing the right installer is just as important as choosing the boiler.
Serviceteam provides Baxi boiler installation in London for replacements, upgrades and new installations. Before the final model is specified, a Gas Safe engineer should assess the property's heat loss, hot-water demand and incoming mains performance; the written quotation should reflect the agreed installation scope.
