no hot water with my combi boiler?

there is no hot water with my combi boiler, but the central heating is working ok. why is that.
alanrutherford69@msn.com worcester bosch 240 boiler, March 2005


done
i agree with tony,just replaced mine and its ok cost me £12 50 inc

austin, November 2006
Probably the heat exchange diaphragm needs replacing ( hole in it)

tony, August 2005