I've recently fitted a power shower for a friend (I know, I should have run a mile...)
It's one of those all in one wall mount showers that basically takes tank pressure hot and cold feeds and pumps them to the head, with a non- thermostatic mixer. Sort of like the separate pump and mixer type, but all in one box over the bath. It was a replacement for an existing one of the same type but different make.
However... although it appears to work at first, it won't go hotter than lukewarm even though the hot feed is *hot*.
After talking to the Creda techies, it loks like it's quite sensitive to (a) flow and (b) balanced pressure on the hot and cold feeds.
The cold is a 22mm feed from the header tank then a 15mm drop inside the wall to the shower. The hot is a 22mm feed from the top of the cylinder, down under the floor then along to the head of the bath, then a 15mm feed back from there along the bath and up the wall to the shower - obviously losing a noticeable amount of pressure on the way compared to the cold.
I was thinking that to put this right, I'll need to run a more direct feed from the top take off of the cylinder direct to the shower. Unfortunately the cylinder is in a cupboard across the landing from the bathroom, so a level pipe run is impossible.
If I run 22mm up to the loft and across, then drop 15mm to the shower, that will be almost exactly the same path as the cold takes. *Except* for the lift from the tank to the loft.
Before I start hacking it all about to do that, I thought I'd check with you lot whether you think that will work?