Mixer Shower with Pump Pipe Sizes

Hello,

I wonder if anyone can help. I am about to install a mixer shower with a pump next to the hot water tank.

The shower comes with 22mm inlets and these are a fixed distance apart. There are also some cranked reducers 22mm to 15mm which the intructions only refer to if you need to adjust the distance between the inlets.

As I am installing from scratch I do not need to use the adjusters as I am installing new pipework.

So do I run the shower on 22mm piping all the way from the pump? Or should I convert down to 15mm at any point and if so why?

Thanks for your help.

Neil

FOr short runs it makes no difference whether you use 15 or 22. Think of the diameter of the hose - which takes both H&C.
I wouldn't dream of NOT usung the cranked reducers supplied. If you use one at 90º to the other you can turn one or other slightly to get your mixer exactly fitting the pipes, and horizontal.
Chrome volcano shaped shrouds usually screw on the 3/4" threaded bit to hide the hole in the tiles.

Hello,

I see what you mean but I cannot see the point of running 22mm from the pump then converting to 15 when the shower accepts 22mm.

Anyway will see how it works

Don't do that, just run 15mm from the pump. If you had a 40ft run you'd need 22mm.
Lots of things have 3/4" fitting they don't need, like a washing machine tap.