Hot Water Troubles

[Nevets1975]

i have a worcester 24cdi combi boiler which has worked fine for the two years i've lived in the house. recently though the hot water has been getting less and less powerful. the hot water temperature is fine but when a cold tap is turned on the hot water goes off. looking at the boiler when this happens i saw the arm from the heat exchanger which operates the microswitch retracts when a cold tap is on so the boiler thinks there is no longer a hot water demand and switches off

i got a boiler man to come take a look and he replaced the diaphragm but this hasn't fixed the problem. a friend suggested a pump for the hot water supply but at £250 it seems a bit risky incase it doesn't fix the problem. can anyone suggest anything else which could be causing this?

 

[kirkgas]

do not fit a pump as it simply will do more harm than good, if it wasnt required before it wont be required now, start with the basics, checking other cold taps etc to see if they are as strong as they were, if not the problem is with the incoming main, if they are ok you need to look at the inlet to the boiler(the most probable cause) there is a filter in the inlet of most combis which might be blocked, do you have the MI's if so have a look and see if it is a task you can take on if not you will need to get a plumber/heating engineer to sort it for you.

 

[Nevets1975]

What a fantastic help, thank you. i checked the mains first and found the tap had not been fully opened after the work done on the boiler. then i decided (feeling very adventurous) i would check the boiler inlet. a nightmare to get to, pretty much had to strip the boiler right down to get at it. but worth it cos the filter was all gunked up. having done all this the boiler back up and running as before. Thanks again for you help