WOW - What can I say, from start to finish the whole process was so smooth. Our existing Boiler a Worcester Bosch Greenstar was not that old but so many issues with it failing so after water poured out of it when turning the pressure up we decided for a change. Had a Viessmann Vitodens 100-W installed. Heatable office personnel were all so friendly either by Web chat or telephone. The engineer was so thorough and what a fantastic clean job he did. The Boiler is stunning, so quiet, remote controlled, hot water delivered in an instant and the heating system so powerful This was a fantastic customer experience from start to finish and cannot speak highly enough of Heatable very thorough in every aspect. If you are thinking of changing your boiler this has to be the Company to go to. We have received Gas Compliance certificate and warranty info with the full 10 year parts and labour warranty. A VERY HAPPY CUSTOMER, thank you