Baxi is a British boiler manufacturer with over 150 years of history, based in Blackburn. The 800 combi represents their flagship residential offering and competes with mid-to-premium combis from Worcester Bosch and Vaillant.
Efficiency
The Baxi 800 achieves up to 94.9% ErP seasonal efficiency — firmly A-rated and competitive with the major premium brands. In practice, this translates to low running costs comparable to the best combis available.
Hot water performance
Available in 25, 30, and 40 kW outputs. The 40 kW variant delivers impressive hot water flow rates (approximately 16 L/min), making it suitable for homes with two bathrooms used simultaneously.
Warranty
10 years with registration via Baxi's Assure warranty scheme. Annual servicing required to maintain the full term. Competitive with Vaillant's Plus range.
Build quality
Good — the 800 uses a stainless steel heat exchanger and has a solid reliability record. Our engineers report it as one of the more straightforward boilers to service.
Connectivity
Compatible with Baxi's own smart controls and major third-party thermostats via OpenTherm. The Baxi app is functional if not as polished as Worcester Bosch's offering.
Verdict
The Baxi 800 is a genuinely strong boiler that often gets overlooked in favour of the bigger brands. For homeowners who want proven reliability and a solid warranty at a slightly lower price point than Worcester Bosch 8000 or Vaillant Plus, it's an excellent choice.