Hi, Sounds very much like the diverter valve is passing, or the diverter valve motor isn't motoring over fully. try removing the motor and running the hot tap, see if the motor moves fully over, if it does, then it will be the valve, if it doesn't then it will be the motor. I'm pretty sure removing the motor is just a click and a twist, no water will come out so you should be ok on that score.
(I book mark all the pages I post answers on, so let me know how you get on.)
LTGF, August 2008
