shower valve

[monkeychum]

I've got a 3/4" triple control thermostatic shower valve to install. Does it have to be piped up in 22mm pipe, it will be running off a combi boiler as the old pipework in the bathroom is 15mm. Also the pipework taht will be feeding the shower head does that have to be in 22mm pipe. Thanks.

 

[ajs heating]

its running from a combi.
so i take it it has a 15mm hot water outlet. so 15mm will be ok as fitting 22mm won't give any better performance if the boiler outlet is only 15mm.

check the mi's to make sure the boilers dhw l p/min is ok for the shower valve.
the boilers dhw l p/m maybe enough to give the shower a good performance if you are using a large shower head etc.