In article , ejl
writes

OK.....half an hour on and darned thing is now working again...should I
worry about this and call a plumber or should I put it down to gremlins in
teh system and forget it?

Since you say the power light on the unit went out, it's an electrician
you want, not a plumber. And with the current drawn by electric
showers, a loose connection is Not A Good Thing.

It may have simply overheated and cut out (though looking out the window
this morning, I rather doubt it). But you would be wise to have someone
who knows what they are doing give it the once-over.

--
..sigmonster on vacation