New toilet and basin not triggering pump

[Cliff McDiarmid]

Hi

I've extended an existing system in a bungalow with a loft bedroom. The existing Stewart Turner pump(over 5yrs)is in the airing cupboard on the ground floor above the tank but at least 60cm below the 50 gall storage tank in the loft. The twin pump does two showers at the moment on the ground floor, the water is pumped into the the loft floor and then down to the showers.

I've installed a toilet and basin in the loft bedroom and connected them into the hot and cold shower feeds under the floor. However they don't trigger the pump. They did before the toilet and basin were connected, i.e. through hoses only, which is odd. If I trigger the pump downstairs at the showers then the toilet and basin will work, but as soon as they are shut off the pump ceases to trigger.

Sorry about the essay, just trying to set the scene. Any ideas here? If the pump was a positive one surely it wouldn't pump the toilet and basin at all.

thanks

Cliff

 

[Newboy]

You need a negative head pump.

When you trigger your existing (positive head) pump by running the ground floor outlets then it will supply the loft outlets. When you open just the loft outlets there is no flow to trigger the pump.

 

[Cliff McDiarmid]

Thanks Newboy. So although it pumps into the loft floor at present the extra height of the basin and toilet is too much for it? How is it that it work before the appliances were connected, I didn't have to trigger the downstairs showers at that point? Cliff

 

[Madrab]

Yes, think of the height of the shower pipework as the shower head, even when some of the pipework is above that. As the shower heads are below the cold water cistern there is enough gravity water flow through the pipework to trigger the flow sensors on the pump. As the basin/toilet outlets are level/above the cold water cistern in the loft, there is not enough/no gravity flow through the pipework to trigger the pump switches, ergo no pump.

Negative/universal pump is needed as @newboy suggests

 

[just pumps]

Not sure I read this right, the shower pump also feeds the toilet cistern?

 

[Cliff McDiarmid]

Thanks. Yes it also feeds cistern. Just to be certain as the existing pump is inaccessible at present. It is a Aura 2.0 bar Stuart Turner pump. Can anyone confirm it's a positive pump? Cliff

 

[Cliff McDiarmid]

Thanks. Yes it does feed cistern. Does anyone know if the Stuart Turner Aura 2.0bar pump was a positive one. Thanks. At the moment the pump is inaccessible so just making sure. Cliff

 

[Madrab]

Hard to say without seeing it, if it was a negative head pump though, it wouldn't be suffering from the issue you are currently having.

BTW, the pump was made for Plumbase etc by ST, but isn't badged as an ST pump, if you see what I mean.

 

[Cliff McDiarmid]

Many thanks. Changing pump.

Cliff