Plumbing advice needed

[jonny the plant pot]

OK, I'm the other half in question here so I'll hopefully be able to answer some of the questions.
The system we have at the moment is a private water supply fed directly from the stream coming off the mountain/hill behind us (therefore giving a vast range in temperature of the incoming water)
The water is stored in a collection tank which is about 40-50 feet above the level of the ground floor bathroom (would I be right in thinking this gives about 1 ½ bar?)
The water passes though a pair of string filters and a UV before entering the house.
All the cold water in the house is then fed directly from this, as is the thermal store (Thermal Store | McDonald Engineers) which is heated using either an immersion heater or the back boiler of the 4kw wood burner. From this tank 2 small radiators fed as well.
The only cold water store is a very small header tank for the radiators.
At present we have an 8kw electric shower.
I've looked at getting either a power shower or a larger electric shower, my thoughts are that the 140 litre thermal store may prove to be too small to fit a power shower, I don't want to be in a position where the radiators end up cold after a couple of people have had a shower.
As mentioned to fit a 10kw+ electric shower would require an upgrade to the wiring but I'm currently thinking this would be the cheapest option. A 10.8kw shower is available from around £140 which I'd fit myself, plus the cost of the electrician to rewire (obviously before the new shower was fitted .��)
To fit a power shower would require a pump fitted, with its associated wiring costs, and a reasonable amount of plumbing work (which I'd do but there's still a cost of parts etc)
Any thoughts/suggestions on any of the above would be greatfully recieved.
Bob

Power showers have the pump built in that's why I suggested it for you .the pump you might be thinking of is a booster pump for mixer valves on gravity fed systems

[Rocketron]

Make of shower would be a start, followed by how high above the shower rose is the top of the water storage tank and then is the tank always topped up?

An 8.5Kw shower will usually deliver about 5lts of warm water but this does depend on the temperature of the water entering the shower.

If you can take a pic of the front of the shower I may be able to go into specifics.

First bit of advice don't jump the gun, I have just priced up for a shower change from an 8.5 to a 10.7. Shower unit top of the range Mira as near to £300 as makes no difference, upgrade from 6mm to 10mm cable with circuit breakers electricians price £480 and then there's my lads labour. You don't want to be spending that sort of money if the water supply is not up to scratch.

Pics are definitely essential, especially with the shower working.
A "selfie" would be ideal.

[Potstubsdustbins]

Hi Bob,

I have had a little check round but do remember showers vary from manufacturer to manufacturer.

If we work at 45 feet of head as a mid line you will get a static pressure of approximately 19.5psi or 1.35bar. A Mira sports max for instance requires a minimum head of 1 bar to function correctly so that bit should be OK.

Next check your water flow rate you will need a absolute minimum of 12ltrs per minute, at this level it would not be advisable for someone to use the water supply whilst someone else is showering.

I agree with your comments about your 140ltr hot water storage, your only going to have about 100ltrs usable at any one time and a half decent power shower would soon use that up. Add to that you would be drawing cold water from the inlet that also feeds the hot water store you would need a good supply for a stable performance.

As to the electric supply, you seem to be a handy chap so if you know a friendly 'sparkie' you could always pull the 10mm cable in yourself, leaving the connections to the professional, that would cut the cost down considerably.

Remember to check the shower specs before you buy, some showers are only good for mains pressure which is far higher than what you have.

[Bigmallly]

Pics are definitely essential, especially with the shower working.
A "selfie" would be ideal.

I don't think Bob would be up for posting a selfie for you................

[veggiechicken]

Here ya go, Rocketron

[Potstubsdustbins]

Nearly forgot,

I have assumed that as your water comes from a natural source it would be 'soft' water, if how ever its above 200ppm calcium carbonate you will need to fit a scale reducer.

The small high powered heat exchangers in this type of shower are very susceptible to scaling up.

[veggielover1980]

If it was me I would give it a miss and have a bath. X

[Bobh]

Hi Bob,

I have had a little check round but do remember showers vary from manufacturer to manufacturer.

If we work at 45 feet of head as a mid line you will get a static pressure of approximately 19.5psi or 1.35bar. A Mira sports max for instance requires a minimum head of 1 bar to function correctly so that bit should be OK.

Next check your water flow rate you will need a absolute minimum of 12ltrs per minute, at this level it would not be advisable for someone to use the water supply whilst someone else is showering.

I agree with your comments about your 140ltr hot water storage, your only going to have about 100ltrs usable at any one time and a half decent power shower would soon use that up. Add to that you would be drawing cold water from the inlet that also feeds the hot water store you would need a good supply for a stable performance.

As to the electric supply, you seem to be a handy chap so if you know a friendly 'sparkie' you could always pull the 10mm cable in yourself, leaving the connections to the professional, that would cut the cost down considerably.

Remember to check the shower specs before you buy, some showers are only good for mains pressure which is far higher than what you have.

Thanks for that, its seems I've been thinking along the right lines then.
I'll check the flow and see what were getting at the bath tap, unfortunately there's only a 25mm pipe running down the hill from the tank, I'd prefer to see a 32mm but after we spent 2 days burying the current one I'm not keen to have to do the same again.
As to the wiring, lets just say I wouldn't expect the cost to be overly high to rewire it.

[Tripmeup]

If it was me I would give it a miss and have a bath. X

I have seen some helpful first posts on here, but that's a winner