Shower Booster Pumps :- My Problem and Understanding

[butch4343]

Hi


I wonder if you folks might be able to clarify my understanding of how shower boosters work , at the moment I have a single impellor on the hot tap to my bath/shower mixer and mains cold water to the cold take. If I run full hot the pump kicks in and then if I have to gingerly add in cold , too much cold and the pump cuts out.

I am led to believe that the reason for this is because the mains cold is over powering the hot and running back down to the pump, where the sensor in the pump cuts out the pump as the pressure is high enough, am I right in this?

I have tested out this as a theory by turning down the cold water pressure in the tap isolation valve to the point where there’s hardly any cold water pressure and the hot works fine , except the waters too hot to stand under.

I was considering getting a twin impellor pump to replace the old pump, my question is, it makes sense to say the impellor will boost the hot to a given pressure, in the case of the cold, will the impellor reduce the pressure to the same amount or will it let the higher pressure cold flow through the impellor without reduction? I.e.

Hot is coming in at 1 bar and the pump boosts it to 2 bar

Cold is coming in at 3 bar will the pump reduced the cold to the 2bar to match the hot output.

Or

Will it allow the cold straight through at the 3 bar.

Cheers

butch
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[Dan Robinson]

You can't put the pump on the mains.

 

[sooey]

I was just about to say that , anyway a twin impellor pump should be fed from the same cistern that feeds the hot.

 

[butch4343]

thanks gents

The cistern that feeds the hot, would that be the cold water tank in my loft?

And

How would I know whether my cold taps are mains fed or from a tank in the loft?

 

[sooey]

Yes tank in the loft.
Easiest way is to put your thumb over the spout and turn the tap on, if you can hold back the water easily it's gravity, if you get a face full it's mains.
It's irrelevant what your taps are on anyway, the pump should have a dedicated supply from the cistern and the cylinder.
So don't tee into your tap pipe work to feed it.

 

[butch4343]

Thanks very much mate, that answer my question , its definately mains coming into the bath bath taps