Sime Super 90 DHW/divertor valve problems HELP!?

Just replaced the diaphragm in the diverter valve, and lubricated the spindle with silicone grease. Although the spindle does now rise when DHW is called, the tap needs to be opened quite a lot, and even then it still doesn't quite rise enough to operate the micro switch to fire the boiler.

Any suggestions?

is maybe the inside of the valve sticking and maybe the whole thing needs replacing?
Or, I did wonder if maybe I installed the diaphragm upside down (just a thought)? I installed the part with the spring to the top.

Martin Clewlow
May 2008