I don’t think its the circuits (i.e. the zones). I’ve tried changing the master to be any other zone as well.. none of them output the required voltage when set to master in order open the valve.
I’m thinking it must be something to do with the board.. I haven’t modified anything and it works fine in manual / program modes. Just master zones not working correctly. It doesn’t make any sense..
I’m going to try and reload the software, new version is out than what I have on the SD card of the Pi.
Have ideas of other things I could try..? i.e. to test if it is the board.