The pressure will obviously be more with the pump running, therefore
more chance of leaks. I would be inclined to fit a 13amp plug on the
pump system and plug it into an extension to try it. Be very careful of
the earthing arrangements and do not be tempted to do any more than
test it with this arrangement.
It depends on where the pump is.
Mine is in the airing cupboard in a bedroom. I changed the immersion heater
FCU to a fused one, spurred off a 13amp outlet, and connected the shower
pump using a 3amp plug top for ease of connection and maintenance.
If it's in the bathroom, I would connect to an unfused, unswitched flex
outlet, running off a 3amp switched FCU somewhere accessible outside the
If the supplying circuit is not RCD protected use an RCD FCU. See
The advice looks unanimous. Thanks guys for your help. I'll ensure I
have a plug fitted to it when he does the pluming.
Incidentally what will happen to the pump if i test it without any
water flowing through it (i.e. just air). I've heard this can be
terminal - but is the effect immediate - or does it need to happen for
a few minutes before it dies out on you ?
BTW - I won't be trying this - I was just curious.
AIUI it depends on the construction of the pump, some will self destruct
promto, others will be OK, so unless you know what you're dealing with.....
BTW this is pumps in general and not specific to shower pumps.
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
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
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
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.
| 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
| 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.
A kitchen mixer does not mix the H&C waters inside the tap, if you look
closely at the kitchen mixer tap outlet you should see two spouts (often
concentric, with the cold on the outside so the tap remains cool to touch).
The "mix" happens in the air outside the shower.
A shower mixes the H&C inside the unit, and with a pressure imbalance the
high pressure cold can push the low pressure hot back, so you don't get a
Also, from a safety point of view, you usually only have your hands under
the kitchen tap and can pull them back quickly if it's too hot. With a
shower, you're confined inside the shower cubicle and your whole body is
vulnerable. Most people also expect a kitchen tap to be hot-hot.
| 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
That may be your current lifestyle, but what happens if you have visitors or
change your routine for any reason.
| 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
See first point.
Bear in mind too that if you have your pump sucking from the mains (which
may not be allowed under water regs) and you have low mains flow/pressure,
and you are running the shower, the loft tank will be emptying and its ball
valve will open to refill it. However, if the pump is sucking all the mains
water for the shower, no mains water will go up to refill the tank and then
the HW cylinder, air will get into the pipes (because the ball valve is
open) and you'll have the possibility of another airlock.
If the pump suction and the layout of the pipes is such that the hot water
cylinder is sucked dry, that may do it no good (those cylinders have almost
no structural strength without the weight of water inside them) and as the
heat from your boiler will have nowhere to go the boiler might overheat. All
of this is somewhat hypothetical and worst-case, but it's not sounding like
a good idea so far.
What you really want to do is have H & C waters at similar pressure going
into a *thermostatic* mixing valve. The best thing really is (although I'm
not an expert) to sort out that cold feed piping.
You mean the _pump_ doesn't turn on when you press the button on the
bath/shower mixer tap ? So how do you get the pump to turn on?
I assume you have separate cold feeds from the tank, one for the hot water
(going into the bottom of the HW cylinder) and another for the cold taps in
the bathroom. I also assume your plumber has taken the cold feed to the pump
from the cold supply to the taps.
Which it would, if they are both fed from the same tank in the roof and are
therefore at the same pressure. You can use that trick on a kitchen tap to
clear an airlock in the HW side because the cold is at mains pressure.
I'd get the cold water supply sorted out. If it's an airlock you can test
for and fix it by connecting mains cold water via a hose into a cold tap
whilst checking at the tank in the roof to see if air is blown out of the
connector at the bottom of the tank. This'll show that there was an airlock
and clear it. I'd want to examine the pipework run to try and eliminate
airlocking in future.
Right under the bath at the front in the middle. It's a bath-shower design
so there's a reasonable amount of space there. It's a bit tight with all the
pipes running through to the basin and bath taps (directly above).
Nope - the instructions say don't fix it down so we haven't. Sits directly
on top of waterproof plywood which is in turn screwed into the floorboards
(ready for tiling rest of floor). Only thing holding it in place is the
pipes coming out of the top.
On this model (and the screwfix 2.25 bar one), they supplied push-fit
plastic pipes coming out of the top. They also suggest using as few 90
degree bends as possible. The fact that these push-fit pipes stick up about
8" meant that we would have to have used two very tight bends to get the
pipes back down - they might also have fouled against the side of the bath
which leans out towards the top. Therefore, we've replace the push-fit pipes
with flexible metal braid connectors. Bit pricey but makes removing the pump
far easier. Might put one little screw in there.
Well this is the biggest surprise of all - it's no where near as loud as I
was expecting. I've fitted the Wickes pumps in the past and they sound like
a jet engine. The B&Q 2.0 bar one is very quiet - recommended.
PS. Don't know how loud the 2.25 bar Screwfix was as it never worked :-(
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