I had my central heating pump replaced a couple of weeks ago. A few days later I noticed that our hot water in the kitchen and bathroom was flowing slowly. The central heating seems to be the same as before and the boiler feeds the central heating and hot water. I have checked as far as I can all the valves. I live in an old building, top floor and it is a standard boiler. Sorry for being non technical but any help or guidance would be apprecitred.