I received one of the shower flow reducers free from Eaga discussed sometime ago in this group. Sent for so long ago that I had forgotten about it.
I duly fitted it to save the planet and sure enough it reduced the flow.
I should add at this point that I have a shower pump fitted (silly I know).
Well there I was nicely soaped up and "enjoying" the reduced flow, when suddenly there was a whooshing sound from behind the tiles and the shower stopped. I quickly turned off the shower and there was only a small damp patch on the ceiling below.
On removing the Aqualisa mixer I found that the plastic pipe fitting on the shower feed from the mixer had disintegrated and the pipe forced off.
So if you have a shower pump don't fit one of these flow reducers or the mixer will be damaged by the build up of pressure in the system.
Just one final tip I got the part from the Shower Doctor in Edinburgh, they are cheaper than most other shower spares suppliers and the new part arrived next day. I am nothing to do with the company but I thought they deserved a mention.
The new part was a pig to fit with only a small hole in the tiles to work through, but it is working again now WITHOUT the flow reducer.