Replacing an electric shower

[bk1981]

Hi,
DP and I have a combi boiler and electric shower in the en-suite.
The main bathroom is a standard shower plumbed directly into the boiler.
The on-suite has no direct path to the boiler.

As it's an electric shower and combi setup we understand we can't fit a power shower or pump.

So we were thinking can we fit a hot water tank with imersion heter just for the en-suite? This would avoid complex gas routing. And as there already a mains water supply to the electric shower this could be split off and sent up to the attic easily.

Does this sound like a reasonable undertaking, and has anyone any experience with fitting a seperately or second tank?

Thanks

[PigletJohn]

I don't know that you will get sufficient flow and pressure.

Unless you have a cold water storage tank above the new cylinder, which would be a complicated job, then you will be dependent on whatever cold water is delivered to the ensuite.

I expect it will be reduced every time somebody turns on another tap in the house.

Run the en-suite cold tap into a bucket, time it, calculate litres per minute.

How old is the house? If you do the bucket test at the kitchen cold tap, how many lpm?

I doubt you will find a better option than running the hot pipe to your combi boiler supply.

[bk1981]

Thanks for your reply.

I was thinking you wouldn't need a cold water tank, as we would get a 150l tank thats would do both of us for a shower each I'd think. And if we fitted a pump that could increase the pressure.

I haven't checked the flow in the en-suite yet but it's not that high. Adequate for a tap. Hot water from the combi may be too low pressure.. but need further investigation. If we ran it direct from the boiler would be about 7m with about four 90deg bends. Not sure what pressure drop that would equate to..

The house is relatively new, built in the late 90s I think.

[venys]

To increase our pressure we ended up replacing our supply pipe (which was lead anyway) and making it a bigger gauge. If I remember rightly I needed to check with the water company to see if it would work first due to their own pressure. Cost around £1200 for around 10m pipe moled into the driveway. I wouldn't suggest a pump as it could get quite noisy. Admittedly I have no real idea if it is enough for.a shower in the loft as we still haven't fitted one yet. But at least we are halfway there.

[PigletJohn]

you can't use a pump if you haven't got a cold-water storage tank, as you would be creating suction in the watermain that might draw pollutants into the drinking water. It might also stop all your other taps from working while the pump was running. And would be noisy.

If you had an unvented cylinder it could deliver no more flow and pressure than comes into the ensuite tap.

The larger pipe venys mentions is often the answer, in an old house with the older plumbing system, hence my questions about lpm and age.

[bk1981]

Oh well back to the drawing board! Thank you for your advice.