Hi Ed
Thanks for your comments:

Why not drop it in some descaler?

I would have done this with the original ... except it fell to pieces
as I tried to prise it out of the pipe. They really are made to be
disposed of ... which is why I want to find an alternative supplier.
Can't remember what Triton charge, probably about eight quid each ;-(.


The water pressure may be low in the mornings for reasons beyond your
control. Is the show significantly above street level?
Are you at the top of a sloping street?

It does sound marginal maybe the sensor is down on the shower. Is it
possible to hold you thumb/finger over the end of a MAINS tap?

No, we're 2/3rds of the way down a hill and the water pressure is
strong ... with no discernable difference in the morning.

I will experiment a bit with trying the shower during the day. Any
ideas how the low pressure sensor might work, anyone?

Cheers
jon N