Shower pump issues

[Lofty24]

I have just installed a shower pump into an existing system the header tank is in the loft giving about 3m head and the hot cylinder is on the same level as the shower, the hot feed to the pump is up and over passing the header tank in the loft were it has an open vent pipe. there is a pressure boosting pump on the hot feed from the cylinder that I think has failed as the flow to the shower pump is inadequate and dose not change when you adjust the manual settings.. the flow to the taps in the bathroom is ok but the shower pump is shutting off due to poor flow.

I sealed the vent pip temporarily to see if it was the problem but this didn't have any effect on flow due to air been sucked in.

Please advise.

 

[PlumbBobBob]

how have you connected to the hot cylinder for the pump? can you put some pictures up?

 

[Lofty24]

The pressure boost pump is on the outlet side of the cylinder pumping up in to the loft there is a run of 22mm for 10m then 15mm to the pump and back to the shower the shower pump is at floor level near the bath cant put photos on until I go back.

 

[Mike Jackson]

So you've fitted a shower pump to an already pumped supply?

 

[Lofty24]

Yes I guess that that would have an adverse affect? didn't know it was pumped until I went looking for other issues should I remove a pump and replace the pressure boost pump for a new one?

 

[PlumbBobBob]

the shower pump should ideally be with the hot cylinder so it can push to the shower not pull from the cylinder

 

[Lofty24]

would that not force water up and through the vent pipe?

 

[Lofty24]

Replaced the Pressure boost pump removed the shower pump increased flow to 8 to 9L per min, bath company coming to config the bath.