Best Combi Boilers: Which Brand Is Best In 2019? - â
Types of boiler: Combi, heat-only, system. Price range: £760 - £2,600. Warranty length: Warranty lengths are typically between two and five years. Worcester Bosch is the biggest boiler brand in the UK, by market share. It makes a range of boilers that would suit any type of home. Its boilers tend to be at the more expensive end of the market.