As qualified domestic unvented hot water engineers we can also ensure your home has plenty of pressurised hot water with a Worcester Bosch Greenstore Cylinder. Worcester's Greenstar gas boilers are highly efficient and for the sixth year running scooped the Which? Best Buy for boilers. In addition, Worcester was voted the most reliable boiler brand and having the most satisfied customers among Which? members. Any Greenstar gas boiler purchased and installed by Gas Right is eligible up to a 10 year Guarantee and Greenstar oil boiler installed by Gas Right is eligible up to a 7 year Guarantee (terms and conditions apply).