Mira shower won't turn off

[Caws]

My shower won't turn off. There's a red reset button glowing on it. I've tried isolating it with the pull chord and that shuts the water off, but as soon as I turn it back on and try using it again the same problem occurs.
Any ideas what's wrong with it and how to reset it?
It's a very old model and when I look up the instructions online they only show the brochures for the newer model.

 

[muggles]

And the model is?

 

[CBW]

Possibly the solenoid. However since there's the reset lit, could be something different. As per Muggles, model number would be handy or photo if you don't know.

 

[Caws]

It's a Mira Advance atl thermostatic. It's working again this morning - weird!
Is it usual for the shower to 'run on ' a little once it's been switched off? I've noticed it's been doing this lately.

 

[muggles]

Yes, they're designed to run on to flush out the hot water and reduce limescale formation

 

[Harry Bloomfield]

It's a Mira Advance atl thermostatic. It's working again this morning - weird!
Is it usual for the shower to 'run on ' a little once it's been switched off? I've noticed it's been doing this lately.

I would guess that some moisture managed to get into the buttons, shorting them out as if you were pressing them. Leaving it off has allowed them to dry out. Yes, they are designed to run on after you press stop, to cool the heater element down and prevent boiling.

 

[Caws]

Ah ok. It's dripping now. Maybe it did that before but I haven't noticed

 

[Harry Bloomfield]

Ah ok. It's dripping now. Maybe it did that before but I haven't noticed

That could be the solenoid valve passing, or just the water in the flexible pipe warming up and expanding. My shower drips for several minutes after I turn it off. It even begins dripping when I fill the bath, but it soon stops.