We're in the process of converting a bathroom into a shower room, and want to replace the existing bath with a walk-in shower. Along with this, we ideally want to install a "proper" thermostatic shower (probably with a pump) rather than an electric shower.
Having spent some time scouring the forum for information it seems that to get a decent flow rate to the shower all pipework feeding the pump must be 22mm... hence this question:
Now that we've removed the bath I've been able to determine that the feeds to the taps are both 22mm runs - one from the cwt in the loft and the other from the hot cylinder. The basin & WC supplies were then teed off these feeds via 22m to 15m conversion fittings and 15mm pipe.
Rather than installing new dedicated feeds & another take-off from the cylinder, can anyone see a problem with using the original feeds to feed a shower? The shower room would effectively be single use so the feeds would to all intents & purposes be dedicated to the shower while it was being used... the WC won't be used at the same time as the shower for example!
We've got good cold pressure thanks to the loft cwt but the hot's not as good - hence expecting to need a twin-end pump. Assuming this is the case, there's nowhere in the bathroom to fit the pump (and if using the existing feeds don't really want to fit it in the airing cupboard) so we're considering installing it in the loft.
If we fit a negative-head pump (on the basis that it will be located above the hot water cylinder and on much the same level as the cwt), would there be any issues with taking the 22mm feed through 90 degrees to run it up the wall to the loft, into the pump, with the pump outputs running back down the wall to the shower mixer (presumably also in 22mm)?
Thanks in advance for any comments or assistance!