New shower installation advice

In our new extension we have 3 bedrooms on the first floor.
We want to install en-suite showers in all 3, but our current hot water supply is not man enough to handle them, and we cannot install 3 electic showers as the mains supply will not support all 3 running at once.

One solution I have come up with is to install gravity shower mixers, and to install new cylinders and cold tanks in the attic in the new extension.
I use the plural because I am considering individual small tanks for each bedroom (there are various advantages to this compared to one set of tanks to supply all 3.

My question relates to the supply pressure at the showers.

Most thermostatic mixer showers are rated from 1 bar upwards.

Would a 25 gallon cold tank feeding a 120ltr cylinder connected to the shower give sufficient pressure for the mixer shower. The cold tank could be situated about 1 metre above the cylinder which in turn is about a metre above the shower head.

Any views/comments appreciated.

One bar is approximately equivalent to a 10 metre head of water. The head you are suggesting is 2 metres maxium, which would give a pressure of 0.2 bar, not enough to drive a 1 bar shower.

However, you could use a pump for each shower (or use larger cold tank and hot cylinder and use a single pump) to increase the pressure. If you adopt that approach you need to be careful in sizing the tanks / cylinders to ensure the pump(s) don't run dry. You will also need to follow the manufacturers instructions with respect to how the pumps are connected, particularly to the hot cylinder(s).

The tank(s) and cylinder(s) will weigh quite a bit when full. A 120 litre cylinder contains 120Kg of water, plus its own weight. A 25 gallon cold tank contains roughly the same weight of water. Multiply this by threee and you have getting on for a ton of weight in your loft. More if the tanks / cylinders need to be bigger. Properly constructed bases / platforms will be needed (no MDF), situated so that the load is properly distributed, and with all required covers, laging overflows and access.

Thanks for that feedback.

The weight is no problem as there are some steel RSJ's in the loft space which can be used to support the weight.

As far as the pressures are concerned I was interested to see these which, although they don't specify the bar rating, do state that they are suitable for gravity feed systems with and without a pump, but I'm not sure what 'low gravity' means.

Descriptions of other showers in their catalogue mention use with gravity feed or combi systems but specify that a pump is needed for gravity systems - whereas this one doesn't.

Have a look at the mira Elite ST, not fitted one before but should do the job. Electric shower fed from storage tank in the loft has an internal pump.

LeedsPlumber said:

Have a look at the mira Elite ST, not fitted one before but should do the job. Electric shower fed from storage tank in the loft has an internal pump.

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Can't use electric - 3 of these exceeds the rating of the mains supply to the house if all 3 are on at once.

What about low voltage power showers like the Supajet range. Try http://www.shower-warehouse.com/new...owers/ZSUPJ-2106-201-Supajet-201-Power-Shower

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