Parish wrote in message ...
Ghazali wrote:

Hi

My plumber will be plumbing my shower booster pump (Stuart Turner
Monsoon twin impeller 2.25 bar) to my bath shower mixer this weekend.

2.25bar? You like an invigorating shower then, or is the shower upstairs
from the pump?

We have an S-T 1.4bar twin impeller with about 5m of 15mm pipe between
it and the shower and that is more than powerful enough but the pump and
the shower are on the same floor.

One thing to be aware of is that they are quite noisy so bear that in
mind when siting it. Ours is in the airing cupboard, sat on the slatted
shelf, which is just studded walls and it makes a lot of noise in the
adjacent bedroom. If I'd have thought about it beforehand I would have
put a piece of paving slab on the shelf under the pump. Unfortunately
there isn't room to lower the shelf to retro-fit one.


It's a 2.25 bar because I picked it up second hand off Ebay. However,
I wish I'd read your post earlier regarding noise. I have put the
pump under the bath and on the floorboards. You can imagine the noise
- it's very loud.
I snapped it up because I saw that it was a Stuart Turner Monsoon,
which are very highly recommended and also quite quiet. What I had
failed to research was that it is only the brass bodied ones that are
known to be quiet. Mine
is the 'engineered plastic type'. I had never had experience of a pump
before - and did not realise they can be as loud as they are. Of
course, if I want to put it on a concrete slab that would mean having
to get the plumber round again!

Anyway, in retrospect, having the 2.25 bar (as oppose to being lower)
was a blessing because for some reason the rerouting (due to different
bath position) of the 22mm cold feed from the loft storage has
resulted in very poor cold pressure. (The shower mixer doesn't even go
on when you press the mixer/shower button due to such bad pressure). I
suspect its an airlock, but it could also be the pump. My plumber
tried to suck out the airlock with some but insufficient success. He
also tried to blow it out from the top (near the tank itself).
Subsequent to this I have tried to cover up the mixer with my hand
whilst opening up the hot to try and let the hot run up the cold pipes
- even this has failed. Still, my point is, at least the pump gives me
a decent flow.

If I can't solve this problem of bad cold flow (and also the noise of
the pump)I am thinking of doing the following......its controversial,
so please give your expert comments.

I am thinking of running both the basin mixer and bath shower/mixer
cold taps off of the mains, whilst still having the hot from the hot
cylinder.

My thinking is that I will turn up the thermostat on the hot cylinder
so that it gives much hotter temperature, and then I will only need to
use a small amount of hot flow in the mixer shower, thus utilising
mainly the increased pressure/flow of the cold mains, whilst still
getting a decent temperature.

Now I know it is not the done thing to do this, but before giving your
comments please consider the following:

1. A kithchen sink mixer also usually runs cold off the mains and hot
from the storage cylinder, yet I never hear pple complaining about
'pressure imbalance' for washing up purposes. Why is it any different
for a shower.

2. I usually have an early morning shower, at a time when no-one else
is using any other water supply in the house, so there is no risk of
any sudden temperature/flow change from, say, another tap being used
elsewhere.

3. Because of the usual daily timing of the shower, surely the mains
pressure will also be similar. (I have heard it can vary depending on
how many other pple are using it on the street, or at different times
of the day).

4. If the water is coming through a shower mixer (i.e. pre-mixed), why
would a pressure imbalance between hot and cold have any noticeable
effect?

BTW: I'm not a plumber remember - so please could any
comments/suggestions be of a sort that I can understand and relay to
my plumber in layman's terms.
Cheers