Shower pump outlet: expand to 22mm or keep it 15mm?

[xanthophile]

I am installing a shower pump and rejigging pipework. Pump outlets are 15mm and mixer taps are 22mm. Is there any advantage in me fitting 22mm pipe over the 4m run or should I fit a 15mm run and expand it just before the mixer taps?

 

[Whitespirit66]

I5mm should be perfectly adequate if it's pumped. As you say, use a 15x22mm reducer near the taps or a 15mm x 3/4" tap connector.

http://www.wickes.co.uk/15mm-x-34in...match||plid|&gclid=CImo_4fOl7wCFeXKtAodEkgAfQ

If using copper 15mm is easier to bend and route as well as being cheaper than 22mm. If you need a small piece of 22mm copper pipe, merchants will often sell it by the metre.

 

[chantelle]

Read manufacturers instructions for the pump,it`s all there.