In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I
would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Does that sound reasonable? Anyone ever done it?
--
Cheers,
Roger
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On Friday, 2 September 2016 16:18:24 UTC+1, Roger Mills wrote:
In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar).

It may be a flow problem rather than pressure, but you could try adjusting the pressure up a bit if your valve is an adjustable one.

Owain

On 02/09/2016 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I
would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Does that sound reasonable? Anyone ever done it?

If you have 3 bar then there is a fault or you have an eco restrictor
fitted.

If you fit a pump after the tank you may well cause it to collapse if
you suck too much.

On 02/09/16 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I
would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Does that sound reasonable? Anyone ever done it?

Sounds like ********. I have never got better shower performance than my
mains pressure setups

maybe 3 bar is a pathetic pressure to limit at.



--
The biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

On 02/09/2016 17:23, dennis@home wrote:
On 02/09/2016 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I
would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Does that sound reasonable? Anyone ever done it?

If you have 3 bar then there is a fault or you have an eco restrictor
fitted.


Something's wrong IF it's really 3 bars when water is flowing. But the
OP said it's limited to 3 bars and may be much less.


If you fit a pump after the tank you may well cause it to collapse if
you suck too much.

Maybe not. An unvented cylinder will be much stronger than the normal
copper cylinder, and it will have an air pocket inside. The risk might
be rupturing that? THere are also pressure relief valves, but I imagine
they only deal with over-pressure.

On 9/2/2016 5:56 PM, The Natural Philosopher wrote:
On 02/09/16 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I
would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Does that sound reasonable? Anyone ever done it?

Sounds like ********. I have never got better shower performance than my
mains pressure setups

maybe 3 bar is a pathetic pressure to limit at.



I'd vote for the eco-restrictor. 3 bar should be fine.

Yes indeed and also mains pressure does vary both in the short and long
term, so don't expect a one time measurement to be always what is going to
happen.
Sounds a bit odd to me that this shower is weedy, considering the pressure.
Brian

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"dennis@home" wrote in message
web.com...
On 02/09/2016 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I
would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Does that sound reasonable? Anyone ever done it?

If you have 3 bar then there is a fault or you have an eco restrictor
fitted.

If you fit a pump after the tank you may well cause it to collapse if you
suck too much.

On Friday, 2 September 2016 16:18:24 UTC+1, Roger Mills wrote:

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

3 bar's plenty of pressure. Find the problem/restriction instead.


NT

On 02/09/2016 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar).

Have you checked what the actual pressure into the system is? (it may be
limited to 3 bar by the PRV, but that is not going to help if you have
less than that to start with)?

Next have you checked the flow rate of the cold main?

If both those are ok, then I would suspect the mixer or shower hose/head.

This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

There are a few mains pumping systems about - they have to have
interlocks to stop them pumping should the input pressure fall too far.

However if you genuinely have a usable 3 bar and flow rate, you should
be able to get a very decent shower without.

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I

I would do it at the best cold tape first. The repeat at the shower.

would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Just fitting a shower head with less flow restriction may do what you want.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 03/09/2016 12:18, John Rumm wrote:
On 02/09/2016 16:18, Roger Mills wrote:
In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar).

Have you checked what the actual pressure into the system is? (it may be
limited to 3 bar by the PRV, but that is not going to help if you have
less than that to start with)?


Not recently. I did check the static mains pressure at an outside hose
tap a while ago and - from memory - think that was about 4 bar. But
that's at ground level and my flat's at first floor level, so that will
make a *bit* of difference.

Next have you checked the flow rate of the cold main?


That's something I obviously need to do - and am planning to do - but
I'm not at the flat at the moment.

If both those are ok, then I would suspect the mixer or shower hose/head.


It was a new mixer etc. which I installed when I bought the flat about 5
years ago, and it's never been very good. I've tried several shower
heads - none of which made any significant difference. The best one was
the one from my en-suite at my main home - but still not as good as it
is at home.

This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

There are a few mains pumping systems about - they have to have
interlocks to stop them pumping should the input pressure fall too far.

However if you genuinely have a usable 3 bar and flow rate, you should
be able to get a very decent shower without.


Indeed. I'm going to have to measure both flow rates and pressure here
at my main home, and at the flat, in order to work out what's going on.

Thanks for your comments - and to everyone else who has replied.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Saturday, 3 September 2016 12:18:32 UTC+1, John Rumm wrote:
On 02/09/2016 16:18, Roger Mills wrote:

In my main home I have two power showers - one in the bathroom and one
in the en-suite - both of which are gravity fed with low pressure stored
hot and cold water, and boost the pressure with a pump. They both work
fine.

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar).

Have you checked what the actual pressure into the system is? (it may be
limited to 3 bar by the PRV, but that is not going to help if you have
less than that to start with)?

Next have you checked the flow rate of the cold main?

If both those are ok, then I would suspect the mixer or shower hose/head.

This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

There are a few mains pumping systems about - they have to have
interlocks to stop them pumping should the input pressure fall too far.

However if you genuinely have a usable 3 bar and flow rate, you should
be able to get a very decent shower without.

I guess that if I were to measure the flow rate with the shower head
removed, that would tell me how much water the mains could deliver. I

I would do it at the best cold tape first. The repeat at the shower.

would expect the flow rate to be a lot lower with the head fitted
because of the resistance that it provides. So, if I boosted the
pressure to provide the same flow rate with the head fitted as the mains
provides without the head, I wouldn't actually be trying to "suck" water
out of the mains.

Just fitting a shower head with less flow restriction may do what you want.

FWIW I've had metal lumps partially block showers more than once. Why there are loose metal lumps to begin with I don't know


NT

Not recently. I did check the static mains pressure at an outside hose
tap a while ago and - from memory - think that was about 4 bar. But
that's at ground level and my flat's at first floor level, so that will
make a *bit* of difference.

About a third of a bar IIRC.

On 03/09/2016 13:27, Roger Mills wrote:
On 03/09/2016 12:18, John Rumm wrote:
On 02/09/2016 16:18, Roger Mills wrote:

It was a new mixer etc. which I installed when I bought the flat about 5
years ago, and it's never been very good. I've tried several shower
heads - none of which made any significant difference. The best one was
the one from my en-suite at my main home - but still not as good as it
is at home.

IME (which to be fair is limited - I have only done two or three bar
mixers) I have found the bar mixers are ok, but not as good as the more
traditional mixer valves. I put one in the top bathroom of the loft
conversion I did in the previous place. Water was about 3 bar and heated
by a combi, so at best you have about 15 lpm of water available. The bar
mixer was "ok" (certainly better than any electric shower), but not as
good as the Mira 88 on the bathroom a floor below.

I also fitted a bar mixer on an Aunt's place that had a 24kW combi, and
that again gave more than adequate results at around 8 lpm, but that
might seem a bit tame if you are used to pumped showers doing 15 lpm or
more.

I have a concealed mixer[1] on my shower here, and that is fed from an
unvented cylinder (with the PRV set at 3.5 bar) - it takes its cold from
the PRV balanced output outlet. That gives a very very good shower -
right into the "flay the skin off you" territory if that's what floats
your boat! So with adequate mains supply (large bore MDPE pipe here that
will deliver 30 lpm at 5 to 6 bar) you can certainly get good showers
from an unvented system.

[1] this one:
http://wiki.diyfaq.org.uk/index.php/...ve_(retrofi t)

This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

There are a few mains pumping systems about - they have to have
interlocks to stop them pumping should the input pressure fall too far.

However if you genuinely have a usable 3 bar and flow rate, you should
be able to get a very decent shower without.


Indeed. I'm going to have to measure both flow rates and pressure here
at my main home, and at the flat, in order to work out what's going on.

At least with bar mixers its usually easy to swap one for another, so if
it is the valve that's the limitation, it not much upheaval to try
another. (in fact you could just buy another to try, and ebay it if no
better!)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

wrote:
On Friday, 2 September 2016 16:18:24 UTC+1, Roger Mills wrote:


In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?

3 bar's plenty of pressure. Find the problem/restriction instead.


NT

Agreed, I reckon it's the bar mixer. Is it thermostatic?

On 03/09/2016 17:13, John Rumm wrote:
On 03/09/2016 13:27, Roger Mills wrote:


Indeed. I'm going to have to measure both flow rates and pressure here
at my main home, and at the flat, in order to work out what's going on.

At least with bar mixers its usually easy to swap one for another, so if
it is the valve that's the limitation, it not much upheaval to try
another. (in fact you could just buy another to try, and ebay it if no
better!)


It shouldn't be too difficult to assess the effect of the mixer. The
shower is over the bath, at the opposite end to the taps, and shares the
hot and cold supplies which divide under the bath. So I can compare the
flow at the taps with that at the mixer fairly easily to see how much
the mixer reduces it.
--
Cheers,
Roger
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checked.

On 03/09/2016 17:54, Capitol wrote:
wrote:
On Friday, 2 September 2016 16:18:24 UTC+1, Roger Mills wrote:

In my holiday flat, I have an unvented hot cylinder, so both hot and
cold water are effectively at mains pressure (but subject to a PRV which
limits the pressure to about 3 bar). This hot and cold water is fed to a
bar mixer shower, but the performance is nowhere near as good as my
boosted gravity showers at home. What are the options for using a
booster pump to improve the performance? I guess that you're not
officially supposed to do that with a mains system, but would it work in
practice?
3 bar's plenty of pressure. Find the problem/restriction instead.


NT
Agreed, I reckon it's the bar mixer. Is it thermostatic?


Yes, it is thermostatic.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
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