Why seperate cold supply to shower pump?

[mattcambs]

Hi, hope someone can advise me here.

My wife and I are having our bathroom re-fitted by a friend who has some good experience with plumbing and bathroom fitting.

We want a "power" shower so we asked our friend what he would be able to do without us needing a qualified plumber/electrician to do some of the work. We have a gravity fed system with hot water tank in the airing cupboard.

He suggested he could install a pump in our airing cupboard (which is next to the bathroom) and supply it with hot water from the tank and "t" off the cold water that comes down into the hot water tank from the cold water tank in the attic.

My question: is this possible? We nearly bought a nice Triton thermostatic mixer shower today, but we stopped when we looked at the diagram on the box which showed an entirely seperate cold feed from the attic tank going to the pump.

Can you just "t" off the cold supply from the attic to go into the pump or must it be a seperate pipe and why?


Many thanks,
Matt

[chris_on_tour2002]

shower pumps should always have their own dedicated supply. bearing in mind that whilst the pump is running you will be taking water from the hot water tank. if you tee into the cold water feed for the hot water tank then the pump could starve the hot water tank of water to replenish that which you are taking from it. this could lead to airlocks and overheating of the tank and boiler. a power shower will drain your hot water tank pretty quickly.

it would be much better to run a new pipe from the cold water tank directly to your pump

[marrtin]

The answer is already posted in the topic

[url]http://www.diydoctor.org.uk/forums/viewtopic.php?t=7153[/url]

If this link is not available, view the topic in this forum "Shower pump location and pipe routing"[/url]