I do not get any hot water when I open the hot water tap. The boiler is Worcester 28CDi Combi. The only way to get hot water is to turn the central heating on, only then the DHW demand indicator comes on and hot water is available. With the heating "ON" I can get hot water from the taps. Turning the Heating to "OFF" I get no hot water and the DHW demand indicator does not come on when the hot water tap is opened. Any help will be much appreciated and thanks in advance.

Dave Birdi, May 2008

The problem is caused by the diaphram being puntured in the change over valve, i would not reccomend doing this yourself as it is a very fiddly job, however although worcester reccomend changing the whole valve there is a repair kit on the market for these giovani valves.
Hope this helps

Geoff

geoff, May 2008

flow switch

zzzzzzzzzz, May 2008