Worcester Bosch
The range we fit most, in three tiers. The Greenstar 1000 at £1,999 is the budget entry — a solid choice for a flat or small terrace, 5 year warranty. The Greenstar 4000 (£2,699) and 8000 (£2,899) are the step up: quieter, better hot-water performance, worth it in a family home with a power shower, both on 10 year warranties. Details on our Worcester page.
Vaillant
One model on our list, deliberately: the ecoTEC plus at £2,699 with a 10 year warranty. It is our pick for larger properties and for anyone who wants parts availability for years to come. Our Vaillant page has the rest.
Baxi and Main
Baxi covers both ends. The Baxi/Main Eco Compact at £1,999 shares the budget slot with the Worcester 1000 — Main being Baxi's sister brand. The Baxi 600 at £2,199 is the quiet star of the list: a 7 year warranty at a near-budget price makes it the best warranty-per-pound we fit. See Baxi and Main.
How to actually choose
Ignore brand loyalty and ask two questions: what output do my radiators need, and how long am I staying? Short stay in a small place — take the budget pair. Staying put — the Baxi 600 or a 10-year Worcester or Vaillant earns its extra cost across the warranty. The three-question finder walks you through it.