The shower in my (1930 built) house is fed direct from the bath taps.
The hot water cyliner is in the airing cupboard.

The hot water pressure is very low, not just in the bathroom but in the
kitchen as well.

This makes the shower difficult to use as mixing even a small quantity
of cold water with the hot makes the shower go cold.

Should I fit a pump somewhere to boost the flow of hot water from the
cylinder? If so, where?

In an earlier contribution to this discussion,
Stevethefootycoach wrote:

The shower in my (1930 built) house is fed direct from the bath taps.
The hot water cyliner is in the airing cupboard.

The hot water pressure is very low, not just in the bathroom but in
the kitchen as well.

This makes the shower difficult to use as mixing even a small quantity
of cold water with the hot makes the shower go cold.

Should I fit a pump somewhere to boost the flow of hot water from the
cylinder? If so, where?


A pump located under the bath would be a possibility. *But* you will also
need to plumb in a low pressure cold feed from the cold header tank rather
than using mains. The 2-gang pump will then receive hot and cold at roughly
the *same* pressure, and boost them both equally so that your mixer shower
will work properly.

The purists will also tell you that you should take the hot feed from a
Surrey or Essex flange installed in the hot cylinder rather than just using
the default take-off at the top. However, you can probably get away without
doing that - as I do.
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but is disposable in the event of excessive
spam.

Thanks Roger.

does the Surrey/Essex flange boost the pressure of the hot water?

Stevethefootycoach wrote:

The hot water pressure is very low, not just in the bathroom but in the
kitchen as well.

This makes the shower difficult to use as mixing even a small quantity
of cold water with the hot makes the shower go cold.

It sounds like you have gravity fed hot and mains cold at the bath. If
this is the case you may be able to help the situation with a single
impeller pump bosting just the hot. The better but more difficult
alternative would be installing a new dedicated cold feed from the cold
water tank and using a dual impeller shower pump.


--
Cheers,

John.

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

A pump located under the bath would be a possibility. *But* you will also
need to plumb in a low pressure cold feed from the cold header tank rather
than using mains.

Actually, provided you use a pressure balanced mixer, it is entirely
possible to mix mains cold water with pumped hot water. You simply need a
good mains flow rate and a single impellor pump. I fitted such a system into
my last house and it worked admirably.

In fact, even without a pressure balanced mixer, it will probably still work
very well, but may be a little sensitive to other taps/toilets being used in
the house.

The purists will also tell you that you should take the hot feed from a
Surrey or Essex flange installed in the hot cylinder rather than just
using
the default take-off at the top. However, you can probably get away
without
doing that - as I do.

Indeed. I fitted mine without a flange, but understood that one might be
required if it sucked air. It didn't. However, my cold tank was directly
above the cylinder with flowed bends. A 15mm tortuous feed with elbows would
be another matter.

The best place for the pump is need the cylinder, as they prefer to push
rather than pull. It also means that the kitchen hot tap gets pumped
operation, too.

Christian.

This sounds like a good idea.

Is it just a case of fitting a single impeller pump in line with the
hot water cylinder outlet? That would (presumably) boost the hot water
pressure to all taps in the house. Or should I fit the pump in line
with the feed to the bath/shower?

In an earlier contribution to this discussion,
Stevethefootycoach wrote:

Thanks Roger.

does the Surrey/Essex flange boost the pressure of the hot water?

No. It just takes the water from a bit lower down in the cylinder.
Otherwise, if you have a very powerful pump, it can suck water - followed by
air - from the vent pipe, rather than water from the cylinder. A flange
prevents this - but isn't always necessary, depending on the power and
location of the pump.
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but is disposable in the event of excessive
spam.

In an earlier contribution to this discussion,
Stevethefootycoach wrote:

This sounds like a good idea.

Is it just a case of fitting a single impeller pump in line with the
hot water cylinder outlet? That would (presumably) boost the hot water
pressure to all taps in the house. Or should I fit the pump in line
with the feed to the bath/shower?

This is an alternative to the twin-impellor pump which I suggested earlier,
and involves less plumbing, but doesn't give equal hot and cold pressures -
which may or may not matter.

As far as location is concerned, you can choose how many of the hot taps you
wish to boost, and put it in an appropriate place to achieve this. The pump
will probably be heard throughout the house - which may be a consideration.

[The normal way in which these pumps work is that they have a flow switch,
which detects (gravity) flow when you open a tap, and switches on the pump.
When you close the tap, the flow stops and the pump is automatically
switched off].
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but is disposable in the event of excessive
spam.

"Roger Mills (aka Set Square)" wrote in message
...
In an earlier contribution to this discussion,
Stevethefootycoach wrote:

This sounds like a good idea.

Is it just a case of fitting a single impeller pump in line with the hot
water cylinder outlet? That would (presumably) boost the hot water
pressure to all taps in the house. Or should I fit the pump in line with
the feed to the bath/shower?

This is an alternative to the twin-impellor pump which I suggested
earlier, and involves less plumbing, but doesn't give equal hot and cold
pressures - which may or may not matter.

If you read and understood Christian's post this would all be clear. Using
one in-line pump on the DHW draw-off of a low pressure cylinder and the cold
to all taps via the mains can give equal pressure at the taps for mixing.
You install a 22mm pressure equalising valve after the pump, then both hot
and cold lines are at equal pressure. You could fit a few 15mm equalisation
valves on a few lines rather than a 22mm valve.

Assume: the pump gives out 1 bar, the mains 2.5 bar. When you turn on the
cold tap 2.5 bar is there. Then you turn on the hot and the cold drops to
the same pressure as the hot that is flowing through the equalisation valve.
If someone flushes a toilet and the cold mains pressure does not drop below
1 bar, then no affect.

The idea is not to have an adverse effect on the shower mixer, the most
critical part of the water system. If a separate shower en-suite shower and
someone turns on a bath tap then the pressure is going to drop along the
pumped DHW line. It mat be best to take the bath from the top of the
cylinder and the rest of the taps and shower from a Surrey flange. Then the
bath will not affect the pumped supply. If the bath water from the mains
then fix a low pressure hot water mixer on the bath

As far as location is concerned, you can choose how many of the hot taps
you wish to boost, and put it in an appropriate place to achieve this. The
pump will probably be heard throughout the house - which may be a
consideration.

The Grundfos single impeller Booster pump is quiet, and cheap (about £80)
its selling point.

[The normal way in which these pumps work is that they have a flow switch,
which detects (gravity) flow when you open a tap, and switches on the
pump. When you close the tap, the flow stops and the pump is automatically
switched off].

Thank you all for your quick and useful replies.

I'll put a single impeller pump on the outlet side of the hot water
cylinder and let you know how it goes.

thanks again!

"Christian McArdle" wrote in message
.. .
A pump located under the bath would be a possibility. *But* you will also
need to plumb in a low pressure cold feed from the cold header tank
rather
than using mains.

Actually, provided you use a pressure balanced mixer, it is entirely
possible to mix mains cold water with pumped hot water. You simply need a
good mains flow rate and a single impellor pump. I fitted such a system
into
my last house and it worked admirably.

In fact, even without a pressure balanced mixer, it will probably still
work
very well, but may be a little sensitive to other taps/toilets being used
in
the house.

The purists will also tell you that you should take the hot feed from a
Surrey or Essex flange installed in the hot cylinder rather than just
using
the default take-off at the top. However, you can probably get away
without
doing that - as I do.

Indeed. I fitted mine without a flange, but understood that one might be
required if it sucked air. It didn't. However, my cold tank was directly
above the cylinder with flowed bends. A 15mm tortuous feed with elbows
would
be another matter.

The best place for the pump is need the cylinder, as they prefer to push
rather than pull. It also means that the kitchen hot tap gets pumped
operation, too.

Using a pipe stat and return loop pipe on the DHW draw-off back to the
cylinder, a secondary circulation loop can be added very easily using the
same pump. The return pipe only need be very small bore plastic to thread
through joist, etc, just like cable.

"Stevethefootycoach" wrote in message
ups.com...
Thank you all for your quick and useful replies.

I'll put a single impeller pump on the outlet side of the hot water
cylinder and let you know how it goes.

thanks again!

Check if the mixer has an integral pressure equalisation valve. If not put
one in directly after the pump.
http://www.plumbworld.co.uk/344-0000

Using a pipe stat and return loop pipe on the DHW draw-off back to the
cylinder, a secondary circulation loop can be added very easily using the
same pump. The return pipe only need be very small bore plastic to thread
through joist, etc, just like cable.

In fact, you would want it very thin, as you don't want the secondary flow
to reduce the outlet pressure. Obviously, you can also balance it down with
some sort of valve, too.

I can't help thinking that a single impellor shower pump would be too noisy
for a secondary loop installation, though. Some might not like the low flow
rate and high pressure drop when no outlets are open.

Christian.

"Christian McArdle" wrote in message
.. .
Using a pipe stat and return loop pipe on the DHW draw-off back to the
cylinder, a secondary circulation loop can be added very easily using the
same pump. The return pipe only need be very small bore plastic to
thread
through joist, etc, just like cable.

In fact, you would want it very thin, as you don't want the secondary flow
to reduce the outlet pressure. Obviously, you can also balance it down
with
some sort of valve, too.

I can't help thinking that a single impellor shower pump would be too
noisy
for a secondary loop installation, though. Some might not like the low
flow
rate and high pressure drop when no outlets are open.

Christian.

The Grundfos Booster is quiet. It looks like a normal CH pump.
http://www.heatweb.com/
Scroll to the very bottom.

Doctor Drivel wrote:
"Roger Mills (aka Set Square)" wrote in message
...
In an earlier contribution to this discussion,
Stevethefootycoach wrote:

This sounds like a good idea.

Is it just a case of fitting a single impeller pump in line with the hot
water cylinder outlet? That would (presumably) boost the hot water
pressure to all taps in the house. Or should I fit the pump in line with
the feed to the bath/shower?

This is an alternative to the twin-impellor pump which I suggested
earlier, and involves less plumbing, but doesn't give equal hot and cold
pressures - which may or may not matter.

If you read and understood Christian's post this would all be clear. Using
one in-line pump on the DHW draw-off of a low pressure cylinder and the cold
to all taps via the mains can give equal pressure at the taps for mixing.
You install a 22mm pressure equalising valve after the pump, then both hot
and cold lines are at equal pressure. You could fit a few 15mm equalisation
valves on a few lines rather than a 22mm valve.

Assume: the pump gives out 1 bar, the mains 2.5 bar. When you turn on the
cold tap 2.5 bar is there. Then you turn on the hot and the cold drops to
the same pressure as the hot that is flowing through the equalisation valve.
If someone flushes a toilet and the cold mains pressure does not drop below
1 bar, then no affect.

The idea is not to have an adverse effect on the shower mixer, the most
critical part of the water system. If a separate shower en-suite shower and
someone turns on a bath tap then the pressure is going to drop along the
pumped DHW line. It mat be best to take the bath from the top of the
cylinder and the rest of the taps and shower from a Surrey flange. Then the
bath will not affect the pumped supply. If the bath water from the mains
then fix a low pressure hot water mixer on the bath

As far as location is concerned, you can choose how many of the hot taps
you wish to boost, and put it in an appropriate place to achieve this. The
pump will probably be heard throughout the house - which may be a
consideration.

The Grundfos single impeller Booster pump is quiet, and cheap (about £80)
its selling point.

[The normal way in which these pumps work is that they have a flow switch,
which detects (gravity) flow when you open a tap, and switches on the
pump. When you close the tap, the flow stops and the pump is automatically
switched off].

Thanks for that IMM and Christian. This Grundfos pump sounds a god
alternative to a big power shower pump. Another post to be saved.

wrote:

Doctor Drivel wrote:

"Roger Mills (aka Set Square)" wrote in message
...

In an earlier contribution to this discussion,
Stevethefootycoach wrote:


This sounds like a good idea.

Is it just a case of fitting a single impeller pump in line with the hot
water cylinder outlet? That would (presumably) boost the hot water
pressure to all taps in the house. Or should I fit the pump in line with
the feed to the bath/shower?

This is an alternative to the twin-impellor pump which I suggested
earlier, and involves less plumbing, but doesn't give equal hot and cold
pressures - which may or may not matter.

If you read and understood Christian's post this would all be clear. Using
one in-line pump on the DHW draw-off of a low pressure cylinder and the cold
to all taps via the mains can give equal pressure at the taps for mixing.
You install a 22mm pressure equalising valve after the pump, then both hot
and cold lines are at equal pressure. You could fit a few 15mm equalisation
valves on a few lines rather than a 22mm valve.

Assume: the pump gives out 1 bar, the mains 2.5 bar. When you turn on the
cold tap 2.5 bar is there. Then you turn on the hot and the cold drops to
the same pressure as the hot that is flowing through the equalisation valve.
If someone flushes a toilet and the cold mains pressure does not drop below
1 bar, then no affect.

The idea is not to have an adverse effect on the shower mixer, the most
critical part of the water system. If a separate shower en-suite shower and
someone turns on a bath tap then the pressure is going to drop along the
pumped DHW line. It mat be best to take the bath from the top of the
cylinder and the rest of the taps and shower from a Surrey flange. Then the
bath will not affect the pumped supply. If the bath water from the mains
then fix a low pressure hot water mixer on the bath


As far as location is concerned, you can choose how many of the hot taps
you wish to boost, and put it in an appropriate place to achieve this. The
pump will probably be heard throughout the house - which may be a
consideration.

The Grundfos single impeller Booster pump is quiet, and cheap (about £80)
its selling point.


[The normal way in which these pumps work is that they have a flow switch,
which detects (gravity) flow when you open a tap, and switches on the
pump. When you close the tap, the flow stops and the pump is automatically
switched off].


Thanks for that IMM and Christian. This Grundfos pump sounds a god
alternative to a big power shower pump. Another post to be saved.

What for? Half the information is totally wrong.

Regards
Capitol

Can someone confirm for me please that the Grundfos Booster pump
mentioned here should be in a 'push' configuration rather than 'pull'.
I was under the misapprehension that this type of pump should be fitted
near the outlet, but I am now seeing comments indicating fitting it at
the tank end - this would be a far better set-up for me and far easier
to implement.

Rob

Can someone confirm for me please that the Grundfos Booster pump
mentioned here should be in a 'push' configuration rather than 'pull'.

Pumps fundamentally prefer to push. You would have to go out of your way to
design a pump that prefered otherwise.

One problem with pulling is that you only have 1 bar of pressure before you
get a vacuum. Use much of this pressure loss through pipe losses and you
will get cavitation and other nasties. 1 bar doesn't pull much water if
there is much restriction, such as long lengths of pipework or elbows.

No pump after the restriction can overcome this issue. However, if a pump is
before the restriction instead, the only pressure restriction is that of the
pipework rating. Therefore, you can push with up to 6 bar pressure, which
can lead to a much higher potential flowrate.

Christian.

Capitol wrote


Thanks for that IMM and Christian. This Grundfos pump sounds a god
alternative to a big power shower pump. Another post to be saved.

What for? Half the information is totally wrong.

You've beaten it - *all* the information in your post is totally wrong.
--

mike

"mike" wrote in message
. 1.4...
Capitol wrote


Thanks for that IMM and Christian.
This Grundfos pump sounds a god
alternative to a big power shower
pump. Another post to be saved.

What for? Half the information is totally wrong.

You've beaten it - *all* the information in your post is totally wrong.

I wonder what the sycophant doesn't understand.

mike wrote:

Capitol wrote


Thanks for that IMM and Christian. This Grundfos pump sounds a god
alternative to a big power shower pump. Another post to be saved.


What for? Half the information is totally wrong.


You've beaten it - *all* the information in your post is totally wrong.


Just go away and try to do it. Then you'll find out.

Regards
Capitol

Just go away and try to do it. Then you'll find out.

Hey, come on what sort of posting is that ? we're here to help one
another here and that is just downright destructive.

The thread has analysed the OP's problem and a relatively low cost
solution has been suggested, that I admit I am interested in too, and
then you come along and rubbish without saying what the problem is.
Are you really happy with yourself allowing several of us to go ahead
and invest £100 or so plus time effort only to find there is a
weakness with this set up that you know all about and won't tell us ?

Come on - where's the catch please Mr Capitol?

Rob

"robgraham" wrote in message
ups.com...
Just go away and try to do it. Then you'll find out.

Hey, come on what sort of posting is that ? we're here to help one
another here and that is just downright destructive.


In effect he is calling Christian a liar. He is in the Tory party you know.
The party that tore down the futuristic Festival of Britain site, complete
with Skylon, for spite because the Labour party made it great success.
Strange people indeed.

Now, now - political rants are no better. Definitely OT and don't help
the rest of us get the answer we want.

Rob

"robgraham" wrote in message
oups.com...

Now, now - political rants are no better. Definitely OT and don't help
the rest of us get the answer we want.

The LibDems are going to lace them anyway, and knock them into 3rd place,
and about time too.

Capitol wrote


What for? Half the information is totally wrong.


You've beaten it - *all* the information in your post is totally wrong.


As it happens I've done it, a couple of years ago, and I'm a complete
amateur.

--

mike

robgraham wrote:
Just go away and try to do it. Then you'll find out.

Hey, come on what sort of posting is that ? we're here to help one
another here and that is just downright destructive.

The thread has analysed the OP's problem and a relatively low cost
solution has been suggested, that I admit I am interested in too, and
then you come along and rubbish without saying what the problem is.
Are you really happy with yourself allowing several of us to go ahead
and invest £100 or so plus time effort only to find there is a
weakness with this set up that you know all about and won't tell us ?

Come on - where's the catch please Mr Capitol?

Rob


dIMM is the problem. Christian has already pointed out that the pump
will cavitate if the input flow is too low. If the pump cavitates, then
the pressures will not equalise correctly(ie fast enough). If you
attempt to feed a bath and a shower from two points of the same cylinder
at the same time ( particularly via a Surrey flange), with a pump
sucking on one of them, the odds are that the pump will not have enough
input flow producing cavitation, a pressure equalising valve cannot cope
with this (you will see that the description says "CAN turn a manual
shower into one which doesn't suffer temperature fluctuations--- not
WILL") . The other problem which you will probably see is that the cold
water intake into the tank will be too fast and the hot water in the
tank will not stratify correctly. The result will be a shower which has
very erratic temperature characteristics, as even with a thermostatic
mixer the required correction is just not fast enough. That's before you
start to look at the size of the feed pipes and the required head/flows.
The Surrey flange will not work correctly if there is not enough input
flow into the tank.

Interesting that Grundfoss show an Essex flange in their drawings,
These give more flexibility in positioning and higher flow rates. dIMM
couldn't possibly accept that Essex was a better proposition!

You can't solve a problem until you define it, this had not been done.

Re -reading the thread, my impression is that the OP may have in all
probability a basic flow problem into/through or out of the hot water
tank. Even nastier, the feed pipes from the hot water tank to the rest
of the house may be furred up (downstairs flow is also poor). Is it a
hard water area? Is there a loft tank feeding the hot water tank? First
steps are to check the pipe sizes, hot water feeder tank size and
position(height primarily) and then to measure the hot and cold flow
rates at the bath/sink taps and the kitchen hot tap. Distance flowed
would also be useful in the case of the hot. Given this information,
there is a chance that the first step required would be to replace some
pipework and/or some valves. Pressure equalisation may well be a good
idea, but do bear in mind that it is not the answer to all problems.
Pressure reduction may be an equally valid approach. Roger's experience
is valid in that often you can get away without Surrey/Essex flanges,
particularly if you are a small household and the shower has a fairly
low flow rate. For very high flow rates multiple flanges can be a good idea.

Using a low pressure booster pump as a panacea will not solve the
problem if it is elsewhere. The pump could in some cases give a head
below about 12' if mounted at bath floor level. Shower pumps normally
give heads of 20--80'.

This thread had lots of advice, some very poor due to inexperience
(dIMM) which probably would not solve the real problem.

That's why the thread was not worth keeping.

Regards
Capitol

Capitol wrote:
robgraham wrote:

cut

Using a low pressure booster pump as a panacea will not solve the
problem if it is elsewhere. The pump could in some cases give a head
below about 12' if mounted at bath floor level. Shower pumps normally
give heads of 20--80'.

This thread had lots of advice, some very poor due to inexperience
(dIMM) which probably would not solve the real problem.

I was the one who said he would keep the post. The point of using a
small quiet pump fitted in the pipe, possibly near the shower mixer,
not on the floor, with a mixer with a pressure equalizing valve using
the cold mains as the cold feed is very sound indeed. And very
appealling. Two have said they have already done it and it works and
that is good enough for me. This pump has 1/2" connections and is
unlikely to drag all the water out of the cylinder and only suitable
for one outlet point like a shower. It will suck out of the cylinder
and down the cold feed from the cold tank. If this is 22mm pipe then I
can't see a problem. If it doesn't work then you are right in that
there is a problem elsewhere, like a blockage. The only dim one on this
thread is you and you have a clear attitude problem.

Thanks for that - slight pity you didn't give us that the first time as
it gave Drivel an excuse to pollute the air with his political
dribblings.

Having also reread the initial posting, I would agree with what you are
saying; it would seem that the OP's dhw system has a fault in it that
is creating the low pressure - either due to the configuration, or to
furring up or the likes. A pump therefore is not going to solve his
problem as the feed - either out of the hw tank or into it from the cw
tank - just in't great enough. Cavitation will result.

I am expecting that my set-up - 28mm feed to hw tank and seperate 22mm
feeds to bathroom and the rest will be ok with the Grundfos pumpin the
'rest' feed. The requirement is to overcome a 2.5m head to the kitchen
where her-in-doors had me fit a continental style spray mixer tap which
is on a shower head type hose and consequently a high pressure drop.

Rob

robgraham wrote

I am expecting that my set-up - 28mm feed to hw tank and seperate 22mm
feeds to bathroom and the rest will be ok with the Grundfos pumpin the
'rest' feed. The requirement is to overcome a 2.5m head to the kitchen
where her-in-doors had me fit a continental style spray mixer tap which
is on a shower head type hose and consequently a high pressure drop.

I'm sure this will work, it's just like mine except I've only got a22mm
pipe to the HW cylinder.

Restrictions down the line, plus the cold water feed is as clear as I can
make it, make it work fine.

I would be interested to hear if your showere tap wrks well, when I had
one, a year or so prepump, it was useless, but I like them, and ir=f you
get a fairly brisk shower I'd be tempted to get another one


--

mike

Doctor Drivel wrote:
"robgraham" wrote in message
oups.com...

Now, now - political rants are no better. Definitely OT and don't help
the rest of us get the answer we want.

The LibDems are going to lace them anyway, and knock them into 3rd place,
and about time too.

LOL!

Didn't you notice the drunkard falling on the self destruct button as
he staggered out of office?

mike wrote:

snip

I would be interested to hear if your showere tap wrks well, when I had
one, a year or so prepump, it was useless, but I like them, and ir=f you
get a fairly brisk shower I'd be tempted to get another one


--

mike

I'll report back in due course - may be a rather long 'due' though,
with the schedule as it is at the moment !

Rob

wrote in message
ups.com...

Doctor Drivel wrote:
"robgraham" wrote in message
oups.com...

Now, now - political rants are no better. Definitely OT and don't help
the rest of us get the answer we want.

The LibDems are going to lace them anyway, and knock them into 3rd place,
and about time too.

LOL!

I think it's a good laugh too.

"robgraham" wrote in message
ups.com...
Thanks for that - slight pity you didn't give us that the first time as
it gave Drivel an excuse to pollute the air with his political
dribblings.

Read what I write and learn dumbo.