I switched on a new install yesterday (16+14 outdoor units and nine indoors,seven bs boxes and four bevq boxes).Did the test and all okbut after having it running for about ten mins it all went off on u4 fault,which turned out to be a faulty indoor pcb.So after disconecting the bs box for that unit and reseting the system it all ran.But now i have another problem,with all fan coils on heating one of the outdoor units is icing up(slave)but the master feels like it is doing nothing(no td across outdoor coil)any idea?