Worcester 240 problem

[swinbar]

Anyone help with our sick combi please

HW On: Water from tap is between 57-59C After tap turned off pump operates and heats up all the rads

CH & HW On: Temp at top of first rad 48C too hot to touch.
The temperature dial on the control panel is set at min but it makes no difference to the rad temp at any setting between max and min

Looking through this forum for 240 problems a common fault seems to be the diverter the diaphragm or both
Have spotted the brass Diaphragm but what does the diverter look like

But could this explain the overheating

 

[kevplumb]

View media item 15391

 

[bengasman]

...CH & HW On: Temp at top of first rad 48C too hot to touch.

You can not have dhw and ch on at the same time on this boiler; irrespective of the ch setting, dhw is always available.
48C is not particularly hot, was that a typo?

The temperature dial on the control panel is set at min but it makes no difference to the rad temp at any setting between max and min

Guess the spindle is broken or has come out of the potentionmeter.

But could this explain the overheating

What overheating?