A capable boiler (Vitodens 050-W) but not outstandingly so. Its main letdown is its poor sensitivity to water flow. The kitchen tap, which is within 1m of the boiler, requires opening rather too much before the boiler detects the flow and triggers. My old Ideal Isar 30 (which was the cheap of the cheap) was far more efficient in this manner. Oddly enough the boiler's sensitivity is slightly better when the central heating is running at the same time. Using more water than necessary or desirable (particularly noticeable on a mixer tap) and not very eco so it means it has to lose a couple of stars.