Baxi HE105 - no hot water :-(

Hi all....
Our boiler (Baxi 105HE) isn't providing any hot water.
Heating works fine.
About 6 months ago i fixed the same problem by using a diverter kit from e-bay, but now the problem has occurred again.
I stripped the diverter front again and lightly creased the pin and reassembled it again, but no joy.
The pin doesn't come out when the hot water taps are turned on.
Does anyone know if there's anything else i can do?
Bank holiday cold showers I guess.

Finger crossed that someone may be able to save us from icy bods.

Please, if you have any ideas, we'd be very grateful

Thank in advance
Andy and a very miffed missus.

PS - i did notice a tear in the diaphragm rubber but there are no leaks.
Would this stop the pin from popping out???

Most definatly, if the diaphragm is split it will not work

Brilliant bazdaman, that's the kind of news i was hoping for.
I can fix that

Phew!!!
Thanks again, it's very very much appreciated.

Andy and happier missus