I have a combi boiler and my bath has a mixer tap. There seems to have developed some kind of blockage to the cold tap (even though the cold flow to the sink is fine). I run the bath by first opening only the hot tap but when the water in the bath gets too hot I open the cold but this doesn't allow any cold water to come through. So I have to turn off the hot tap, which shows that nothing is coming out of the cold, and then fiddle about with the cold tap until eventually some cold water comes through but with not much pressure behind it.
Anybody got any idea what the problem might be? Is it likely to be a problem with the tap itself or could it be a problem with the boiler?
