So have set up the RF kit etc.. and all was great until the micro switch on dhw valve calls to the boiler which is old school L,N,E no sw/l and by feeding onto that which is of course linked to a pump it then back feeds 240V to the pump via the linked cable with the switched lines to call the boiler on from cylinder stat or roomstat and by doing so it starts the pump running against a closed Htg valve ! as room stat is still at 0V not calling.
Hope you get what I mean ?
Apparently you can sort this out with a relay ? It might be something simple but I can't see a way round it as yet.