CHANGING A THERMOSTATIC MIXER SHOWER

[j0nb0y]

I am wanthing to change my aqualisa mixer shower for a new one. The supply pipes to the current shower are in 22mm, which go straight into the shower mixer. But all the mixer showers I have seen only have a 12" connector. Is it ok for me to put 22mm to 15mm reducers on the existing pipes and then put a 1/2" female connector onto that? or do I need to find a shower that connects straight onto the 22mm pipes? Any info, from any plumbers, builders, diyers would be much appreciated.

[ELVIS68]

Can`t see why not

[The Builder]

As you say jonboy, just reduce to 15mm, then 1/2 inch tap connectors.

[j0nb0y]

cheers for that, just thought I would check. "the builder" any ideas why the supply pipes are in 22mm and not 15mm? Is this usual for a thermostatic mixer shower run off a low pressure water system? (standard boiler as opposed to a combi)

[The Builder]

Hi Jonboy ............. it's very unusual to take 22mm pipework right up to the valve. The valves themselves often come with varying sized unions to connect onto. Maybe it's a way of making them universally connectable for different systems etc in other countries. I'm only guessing.
It was always good practice with gravity systems, to come away from the tanks in 22mm to get maximum flow (actual amount of water as opposed to pressure). You then get as much water as possible to the valve .......... then reduce or whatever to connect. It's just a matter of preference/convenience as to exactly where you choose to reduce.