If so its back feeding, NRVs are needed to be renew
Again manufacturer to the rescue
Plumbstar Tom, August 2009
sounds like you've blown the pressure relief device
(PRD) contact makers for replacement a good diy person can easily replace it. shower must then re-commisioned by turning the temperture controle to it's hottest position,remove spray head and then switch on
check that shower head is not blocked as this can blow the (PRD) again and you'll be back to square 1 again
