Shower advice

[DaveA]

I am looking to buy an integral unit type gravity fed shower (thermostatic type). I am restricted to installing the shower over a bath at the far end to the taps. There is a window at the tap end so installation here is not practical.
1) What is the minimum head of water which I need. (My cold water tank is in the loft above the bathroom and my hot water tank is in the airing cupboard at the same level as the bath).
2) Is it possible to take the water feeds from the hot and cold bath feeds beneath the bath using T fittings, extending the pipework beneath the bath so I can install the shower at the opposite end to the taps, bringing the pipework up inside the cavity wall at the bath end.
I see no difference in what I propose to do compared with fitting thermostatic bath mixer taps, but there may be issues I have overlooked.
Hope someone can help.

 

[peter anderson]

You are meant to have a special cold feed from the cold water cistern that supplies the shower only. The hot water feed to the shower should be from a T in the pipe that rises in a bend out of the hot water cylinder (I forget the exact distance it should be). The reason for this is that if anyone turns on a tap it won't affect the shower flow.

If you feel happy no-one will turn on any taps I don't really know if your plan will be a problem. Anyone else know?

 

[DaveA]

Thanks Peter.
I understand there are power showers available now which have an integral pump unit. I appreciate I need to draw off non pressurised water but may use this option instead of a gravity fed system.

 

[AlanE]

Best place to take shower hot supply is via an essex flange in side of tank otherwise power showers are liable to suck air down the vent pipe.

Cold supply MUST be at least 25mm below pipe feeding the hot supply at cold water storage tank. This is so that if you run the tank dry the hot always runs out first to prevent scalding that could otherwise occur.

Alan

 

[peter anderson]

Hi AlanE,

I don't want to be a smart arse but my plumbing tutor told us a few weeks ago that shower manufacturers had now agreed that the optimal position for the hot water feed was from the pipe out of the cylinder going down from a T about halfway before the pipe reaches the vent pipe, and that this was preferable to the essex flange position.

 

[DaveA]

Thanks guys.
An essex flange sounds to me like I need to cut a hole in the hot water tank. I like the sound of the "T" - much simpler. I have seen a diagram on a web site which shows a similar installation using a "T".
Maybe it would be best to keep taking baths and forget the shower.
Thanks for the input.
Dave

 

[taydo]

Peter Anderson ask your tutor please, how a tee in a pipe is better than a seperate feed from the tank ie Essex flange. makes no sense to me.

Thanks

 

[peter anderson]

Good question taydo and i will rummage round in my notes and also ask my tutor. My tutor didn't decide that the T option was best herself she said that recently shower manufacturers had agreed that it was the best option. Because the T feed to the shower is the first feed then the shower will have priority hot water supply. I'm wondering if there will be a change in flow(pressure?) to the shower if a hot water tap is turned on and whether this change in flow will be greater than if the shower is supplied directly from an essex flange. Whichever way the shower is fed it seems to me that there will be a change in flow to the shower if a hot water tap is turned on.

 

[peter anderson]

To add to my previous reply I guess the safest thing to do is ask the shower manufacturer of the shower to be installed which option they recommend for their shower