No hot water on water only setting on my boiler, but hot water on heating and water setting, so as l am on a service plan called Scottish power up. The engineer came out and said it was a valve that wanted replacing and Scottish power would ring me when they had the part and arrange a date to fit it. I was called on the day of fitting and told that it would not be done as my boiler wanted a power flush, to which I replied my heating is fine its my hot water that's the problem but they were adamant it wanted doing. I am still waiting for a manager to ring me as I have asked two British gas engineers about my problem and they say the valve should be changed and only if that does not cure it a power flush should be done, It seems they are trying to get some extra money out of me for something that might not need doing because how do they know there is sludge in the system if they have not drained it to find out,