its the stupid relies your getting thats making me go ffs ,and your right i dont have to give a ,but ill point you in the right direction anyway,you wont see an earth fault,by leaving off the kitchen ring,rcd resetting you have narrowed it down to that,next swich off all spurs, remove all plugs,see if it resets,then turn each one back on,if your lucky the spur/plug that you put back will trip,narrowing it down again