Perfect for small to medium sized homes with one bathroom. Modern new design, quiet operation and easy to use full colour text display. Wide power range to efficiently meet all heating and hot water needs. This product should only be installed by a Gas Safe registered engineer. Unfortunately due to the nature of the products and for safety reasons, we cannot accept returns on unwanted boilers (your statutory rights are not affected). Worcester Bosch Worcester Greenstar Combi 4000 Boiler 25kW in White Worcester Bosch Greenstar 4000 Combi Natural Gas Boiler 25 kW offers an attractive design, improved installation and excellent performance. Er P A-rated for energy efficiency and water heating efficiency, this 25 kW condensing combi boiler includes an intuitive display panel for ease of use. 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. We’ve raised the bar with the speed and ease of installation, commissioning and servicing, alongside improvements in efficiency and control. Ease of installation SimpleSwitch to previous Worcester i Junior and Si models with pre-piping jig offering rear piping as standard Flexibility of siting provided by long flue lengths (up to 12m with 60/100mm flues), 500ml integrated condensate siphon to reduce the risk of freezing and the boiler's ability provide full hot water flow rates in low water pressure areas Complete peace of mind for the end user with a 10-year heat exchanger and a 7-year product guarantee available as standard. Wide modulation range designed to optimise efficiency when heating demand is low. High-end design, quiet operation (up to 45dB(A)) with an intuitive, long text, colour boiler display offering optional intelligent filling solutions