Dear Sir / Madam. Before I contacted you for an engineer to replace my divertor valve as it appeared to not be working correctly. After failing to turn up on numerous occasions , you still charged me for the engineer NOT turning up.?? I still hoped to get it replaced. So we waited and contacted your service centre for another attendance. After your final attendance and attempting to change the valve I find that to date you have charged me £400 and I am now worse off , after your repair ???? I now have no hot water. I haven't had time to see if the heating works yet ! I have contacted another company in the hope they know how to deal with a Viessmann condenser boiler. I feel you have over charged me for the service I have received. They did reply to my message 😔 But alas it basically said tough.