Thanks very much everyone for the suggestions.
I tried the *free* and *easy* solution first and cleaned out the handset.
It didn't seem clogged, but i must say I enjoyed much better water pressure this morning and I am cautiously optimistic that the problem is solved :)
No plumbing...
My electric shower has recently started acting up.
It starts off fine - both heat and pressure.
Then there is a soft click or pop from within the unit
And the water goes cold suddenly.
Then it heats back up again.
Then a few minutes later, another click and I dodge the cold water again...