Timer i changed the timer unit powered up and reset the clock great. however next day after realising i had set the clock a hour slow tried to change the time and it wont let me (this was the original problem )it keeps going to auto and the only way to clear it is turn of the power off the clock goes back to 12 o'clock

After you set the time ,do you push the Clock button to lock your time??If you set the clock time and walk away its not holding the time ,because its waiting for you to confirm time selected.So after you set the time press the clock key pad 1 more time .Remember this, just because you bought a new clock doesnt mean its a good part.Bad parts get the best of us ,so dont think your new part is ok yet.It probably is not.