I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

1.5 bar enough for one shower?
Can an extra shower be added to the pipework, probably cannot be used at
the same time, but I cannot see why one should not be fitted, so they
have the pump supplying the main bathroom and en-suite.

Surrey flange - essential, or can I 'T' into the tank outlet?

What about thermostatic mixers - the cold will be a low flow at many
times, do the pumps cope with the difference in flow between hot and
cold?

Thanks
Alan.

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To reply by e-mail, change the ' + ' to 'plus'.

On 04/11/12 09:20, A.Lee wrote:
I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

I have no great experience but that is what I have done, taking an
entirely new feed from the tank. Doing it this way, prevents other loads
altering the cold pressure and it has worked well for many years.

Andy C

"A.Lee" wrote in message
...
I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

1.5 bar enough for one shower?
Can an extra shower be added to the pipework, probably cannot be used at
the same time, but I cannot see why one should not be fitted, so they
have the pump supplying the main bathroom and en-suite.

Surrey flange - essential, or can I 'T' into the tank outlet?

What about thermostatic mixers - the cold will be a low flow at many
times, do the pumps cope with the difference in flow between hot and
cold?


Our previous house - larger hot water cylinder (plumber fitted the shower
pump to 'see how you go' and we emptied it pretty quickly) to replace the
'normal size' tank.

Large dual impeller pump - one feed from the cold tank in the loft and one
from a Surrey (or similar county) flange at the top of the hot tank.

With this setup and 22mm pipework we could run two showers at the same time.

You do need a large header tank in the loft to avoid sucking it dry.

IMHO it is safer to have hot and cold at the same pressure from stored
water - gets away from much of the variability with mains water pressure and
allows you to pump more water than the incoming mains can supply in real
time.

HTH

Dave R


--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

(\__/)
(='.'=)
(")_(")

On 04/11/2012 10:08, Andy Cap wrote:
On 04/11/12 09:20, A.Lee wrote:
I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

I have no great experience but that is what I have done, taking an
entirely new feed from the tank. Doing it this way, prevents other loads
altering the cold pressure and it has worked well for many years.

Andy C

Similarly ours is fed from cold tank/hot cylinder precisely to moderate
pressure differences - though our shower is a very modest one which
wouldn't really qualify as a power shower - simply decently usable where
the previous one was a dribble.

I did make sure that the downstairs WC was plumbed directly from mains
partly to avoid that suddenly changing pressure. And the bathroom WC has
its own direct-from-cold-tank 15mm feed. And other than the cold supply
to the modest downstairs hand-basin, and hot-supply to the kitchen sink
nothing else is going to dramatically or suddenly affect the available
water pressure - and if the person in the bathroom chooses to turn the
basin or bath taps - that is their look-out.

--
Rod

In article ,
(A.Lee) writes:
I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

You need to take the cold from the tank too, from an outlet which
is lower than the feed to the hot water cylinder, so that if the
tank runs out for any reason, the hot stops first and the person
in the shower doesn't get scalded.

There are fast acting shower mixers which include this protection
instead, but they're expensive.

1.5 bar enough for one shower?

Yes.

Can an extra shower be added to the pipework, probably cannot be used at
the same time, but I cannot see why one should not be fitted, so they
have the pump supplying the main bathroom and en-suite.

Yes. You'll probably find you can use both at the same time.

Surrey flange - essential, or can I 'T' into the tank outlet?

Mine is T'ed into the cylinder outlet, without any apparent
problems. It is T'ed in after the top pipe has dropped a good
2/3rds way down the side of the cylinder, and this might be
to help ensure it doesn't suck air back down the expansion
pipe (which it doesn't).

What about thermostatic mixers - the cold will be a low flow at many
times, do the pumps cope with the difference in flow between hot and
cold?

A thermostatic mixer is not essential in a stored water
shower, and if you do have one, it can be one of the cheaper
(slower) wax pellet types. If you happen to be going to France,
identical shower mixers of this type are about 1/4 - 1/3 of the
price there, compared with here.

A dual impeller pump will cope fine with flow in only one side.
Mine has flow sensor switches in both sides, and either one
switches it on. (Actually, it's one switch, with magnets in
both sides.) If I'm heating water just for the shower, I only
heat the hot water cylinder up to the right shower temperature,
and then use the shower valve entirely on hot. (If legionnaires
disease worries you and if your parents are elderly it probably
should, this is not a good idea.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 04/11/2012 09:20, A.Lee wrote:
I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

No, you need equal hot and cold pressure

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?


Yes. And the cold feed to the shower should be below the cold feed to
the cylinder so that, if the tank empties, the hot stops first
[Having said that, mine are at the same level, and I've never had a problem]

1.5 bar enough for one shower?

Probably ok for a reasonable - rather than invigorating - shower.

Can an extra shower be added to the pipework, probably cannot be used at
the same time, but I cannot see why one should not be fitted, so they
have the pump supplying the main bathroom and en-suite.

Depends on geography. You'll need to take hot *and* cold from the pump
to the second shower, when it might be easier to run a separate cold
feed from the header

Surrey flange - essential, or can I 'T' into the tank outlet?

Probably not necessary with a 1.5bar pump. I've got two pumped showers,
each with its own pump, and both effectively tee'd into the cylinder
outlet, and they're both fine


What about thermostatic mixers - the cold will be a low flow at many
times, do the pumps cope with the difference in flow between hot and
cold?


Depends a bit on who else is using water at the same time. Both my
showers have manual (non-thermostatic) mixing valves, and I've not had a
problem. The temperature changes a bit when I adjust the flow rate -
probably due to different resistances in the hot and cold feeds - but,
in my case, it always goes colder if I reduce the flow - so no danger of
scolding.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

A.Lee wrote:

I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

When I moved into this house, it had a pathetic gravity fed, surface
fitting Mira thermostatic shower, initially I did a quick fix ...

Cheapo dual impeller pump 15 mm teed feeds from the existing top outlet
of the hot tank, and the cold inlet to the hot tank. This made the
shower usable but nothing special.

When the cheapo pump went on the blink after 2-3 years I did more of a
refit.

separate 22mm feed from cold tank, 22mm techflange(?) feed from hot
tank, salamander RSP75 pump, reducing after a couple of feet to 15mm
with swept bends for the main run from airing cupboard to shower. Mixer
was replaced (for a similar Mira flush fitting thermostatic).

That got me a shower than can *really* drill into the back of your neck,
the 2.2bar is actually a bit much for a "normal" showerhead, with the
narrowest spray pattern and the mixer flow on maximum, water ****es out
of places on the showerhead where it shouldn't, but with today's dustbin
lid sized showerheads that's probably not an issue.

However it can also drain the cold tank in rapid order without
assistance from teenage daughters, I should probably replace the ball
valve with one that lets the tank refill more enthusiastically.

Can't say whether an "Andy Hall class" pump would be worth the extra, I
haven't had a peep of trouble from the salamander in ~6 years.

If fitting another shower for myself, I'd go the flange + reasonable
pump + 22mm feeds every time ... On the other hand, my parents seem
content with showering under the equivalent of two Jif Lemons :-)

On 04/11/2012 09:20, A.Lee wrote:
I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

1.5 bar enough for one shower?
Can an extra shower be added to the pipework, probably cannot be used at
the same time, but I cannot see why one should not be fitted, so they
have the pump supplying the main bathroom and en-suite.

Surrey flange - essential, or can I 'T' into the tank outlet?

What about thermostatic mixers - the cold will be a low flow at many
times, do the pumps cope with the difference in flow between hot and
cold?

Thanks
Alan.


Double pump, Surry or similar flange. Get a Stuart Turner pump if you
want it to last (will also be quieter than a shed basic)

On 04/11/2012 09:20, A.Lee wrote:

I'm fitting a shower pump for my parents, done them before for customers
who have bought the parts themselves, but never bought one myself.

Single shower, so do I go for the single impeller to pump the hot water,
and use the mains pressure cold?

Or, go for the double impeller to pump hot and cold, and add an extra
feed from the header tank to feed the cold water side?

That is the more normal arrangement. Worth checking that the main
cistern can refill fast enough. Sometimes fitting a pair of fluidmaster
type valves on the cistern can ensure it can keep up.

1.5 bar enough for one shower?

It will be significantly better than gravity alone. It might not satisfy
those that crave the being pressure washed experience.

Can an extra shower be added to the pipework, probably cannot be used at
the same time, but I cannot see why one should not be fitted, so they
have the pump supplying the main bathroom and en-suite.

If the pipework is 22mm, then possibly. Most modern showers will give a
decent enough experience on 7 or so lpm. I would fit a more powerful
pump if doing two though.

Surrey flange - essential, or can I 'T' into the tank outlet?

I did a 1.8bar stuart turner pump on a normal hot water outlet and it
was fine. That was with a nice easy and direct run from the cold cistern
to the HW cylinder though.

You could also make up a warinx type flange using the existing outlet on
the cylinder as an improvement measure on the normal one without needing
to go as far as actually changing or adding a flange.

What about thermostatic mixers - the cold will be a low flow at many
times, do the pumps cope with the difference in flow between hot and
cold?

Yup - they allow "slip" as such - so blocking one side does not stall
the pump.

--
Cheers,

John.

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

John Rumm wrote:

On 04/11/2012 09:20, A.Lee wrote:

I'm fitting a shower pump for my parents,.....


Thanksto all for the input. I'll be going for a double impeller pump
to feed both showers, run off a surrey flange (just in case!).
Make of pump is unknown, price is a factor, so it may be a Grundfos or
Salamander.


Thanks
Alan.


--
To reply by e-mail, change the ' + ' to 'plus'.

In article , A.Lee
scribeth thus
John Rumm wrote:

On 04/11/2012 09:20, A.Lee wrote:

I'm fitting a shower pump for my parents,.....


Thanksto all for the input. I'll be going for a double impeller pump
to feed both showers, run off a surrey flange (just in case!).
Make of pump is unknown, price is a factor, so it may be a Grundfos or
Salamander.


Thanks
Alan.


FWIW ... recommend Stuart Turner Pumps...
--
Tony Sayer