On 04/06/2018 09:03, Nightjar wrote:
On 04/06/2018 07:26, harry wrote:
On Sunday, 3 June 2018 22:11:31 UTC+1, StephenÂ* wrote:
HI

I soon will have several IBCs at ground level to collect rain water.

(I have new pipework in place for the toilets and outside taps which all
go back to the loft, its currently connected in the loft to a mains
water pipe)

I have a cold water cistern in the loft which I can connect up to the
house toilets and the outside taps.

Now where can I find a good value for money submersible pump that I can
put inside the IBCs and pump the rain water to my loft tank, and will
sense when the loft tank is full? I presume I can use a ball cock
arrangement?

S.

You will need two float switches.
One in the ground level tank to shut the pump off when there's no
water.(Opens as water level falls)
Plus on in the loft tank to shut the pump off when it's full. (opens
as water level rises.)

ie they work in opposite senses.

They will be wired in series.
So the pump runs when both are closed.
ie bottom tank is full and top tank is empty.

Or you could use a pump designed for the job, with back-pressure
detection that will turn the pump off when the ball-cock closes:

https://www.guttermate.co.uk/submers...ater-pump.html



Top tank will need an overflow capable of taking away full pump flow.

The overflow should be capable of taking away *more* than the full pump
flow. A rule of thumb is that the overflow pipe should be at least one
pipe size larger than the inlet pipe.

Or have a high-level switch to shut the pump off and a separate
high-high-level switch to shut off the pump, lock it out and raise an
alarm in case the high-level one fails.

That's what I'd do if I were planning such a system (I have thought
about it a few times).

SteveW