Cold water feed to shower

not being a plumber but thinking logically I should imagine its to prevent the cold water running out before the hot and scalding you?? a bit like making the earth lead longer than the rest in a plug top so its the last to be pulled out

just had a thought move the existing feed up 60mm and use the old one for the shower

No hot water is involved.

It just says the cold feed to the shower must be 60mm below the cold feed to the taps etc.

The shower only has a cold water feed. So the cold water can't run out before the hot!! If the feed stops then the shower simply stops.

if that's the case is it not an electric shower fed from mains water pressure and then why the need for a pump unless there are there are pump fed electric heated showers

At a rough guess, is it to limit pressure and temperature fluctuations if someone turns on a tap?

The logic is that at some point they are expecting you to have a shower mixer that will be taking hot water from a cylinder that is replenished from the same tank as you are taking the cold feed. Hence for safety it is better if the feed to the cylinder is exposed first should the water level get too low. That way the hot stops flowing before the cold.

If that is not the system you plan to install then you probably have no need to worry.

... and for the solution to the OP's dilemma, one way is to fit a new tank connector a bit above the existing one. Then move the feed to the HW cylinder to the new one and the cold to the shower pump to the original connector.

This makes sure that hot stops before cold.