Thanks guys. Thought it may have been a big problem. Got a new Triton Seville 9.5kW from Amazon. Not worth messing around with the old one, but thanks for your time.
Hi All.
I have a Gainsborough 9.5e electric shower. All of a sudden the water has gone cold.
I have opened it up and discovered a plunger next to the heater tank bit. This plunger operates a micro switch when pressed with a screwdriver. I presume it usually works via the water pressure...