Agile.
years ago thousands of Vaillant vc110,vc112,vc142 were fitted in the local authorities housing stock. within 3 years it was found that an unusual amount of expansion vessels had been changed. the authority got the manufacturer involved. over a period of time all the exchanged vessels...
you may get water out of the valve but that does not necessarily mean the diaphragm is damaged. it may be a build up of condensation.
if it was originally pressursed with nitrogen then that might be a different story. but thats too much information & is irrelevant.
you drain down first...
thanks i understand now.
as has been said 'pluming' should have been explained to you prior to installation. there may be issues in regard to nuisance by the sound of it also.
thats worth checking.
this is ideally what you want.
yours should be similar but the supply to the hot taps is higher up.
this should still be ok providing this pipe has a fall away from the open vent allowing any air to make its way toward & up & out open vent.
how on earth could anyone even guess.
remove 2 port, fit 3 port. hmmmmmmmmmmm.
another pipe run from somewhere might be in order.
just say what you have, say what you want & the reasons why.