Our Galaxy electric shower is less than 3 yrs old and has had the flow valve
replaced twice already. It's started to fail yet again and cannot be shut
off completely so drips constantly.

I'm considering replacing with a unit that has an ON/OFF switch for flow,
the water supply has an isolation valve which makes life easier and I'm not
completely inept with such things but have the presence of electricity and
water is the reason for my enquiry!

Are these things relatively simple to replace or would I be best leaving to
a plumber?

TIA

Darren