Check valves

[SteveS]

I'm in the process of re-doing the kids' bathroom. The basin will have a mixer tap, and the electric shower will be replaced with a power shower. The basin and bath currently have mains pressure cold and cylinder hot. The mixer tap instructions say I will need a check valve, and I presume I will need one also for the cold feed to the power shower. Can anyone advise me exactly what I need to buy (brand, type etc.) ? Will I need to fit a restrictor to the shower cold supply and if so, can anyone suggest a source? The shower will be a simple integrated unit e.g. Mira Essentials.

TIA,

Steve S

[SteveS]

Silly me. It's not permitted to pump mains water, so it's a separate feed to the shower....

Steve S

[Andrew Gabriel]

Whatever your local plumber's merchant has, I would suggest.

Unless the shower indicates otherwise, I would expect it will require both hot and cold feeds to come from the same tank. The cold should be fed from a separate pipe from the tank whose outlet is lower than that for the hot water, so if the tank runs empty, the hot water runs out first, avoiding risk of burning someone.

You can get mixer showers designed for vastly different hot and cold water pressures (typically for multipoint or combi use). I have one and it seems to include some extra safety checks (like if the cold water supply is off, it doesn't let any hot through at all).

[SteveS]

Ta muchly, Andrew.

Steve S.