Mira shower

[lightfoots]

I have a Mira Zest shower (about 10 years old -not used excessively). I'm sure the flow used to stop almost immediately on switching it off but gradually it has been taking longer and longer, at present about 17 seconds. Also, I leave the shower switched on all the time - i.e. at the source of the electric point (so the red light is always on). Will this be costing much in electricity? I would be grateful for advice. Thanks.

[buildersmate]

It sounds like the flow solenoid valve might be sticking, but if it is eventually turning off completely, is so much of a big issue.
Leaving the little red neon on hardly uses any electricity - maybe 1p per week say.

[lightfoots]

Hello buildersmate. Thanks for replying so quickly and for your help. I'm reassured by your advice, but can I replace the solenoid valve myself, quite easily? If not, I'm happy to let things remain as they are.
lightfoots