Built on all the tried, tested and much-loved features of the Greenstar i, the Greenstar 4000 is instantly familiar and yet totally transformed in appearance, performance and installer plus points. With outputs of 12kW to 24kW, we have raised the bar with the speed and ease of installation, commissioning and servicing. Encompassing features from our range-topping 8000 Style, informed by insights from installers and featuring real advances in siting flexibility, it takes what was the nations favourite boiler and makes it even better