Easiboost Shower Installation

[Willo64]

I have recently installed an Easiboost shower pump. Have followed the instructions to the letter and e.g. not a negative head installtion, keeping the pipes to and from straight, using 22mm pipework to maximise flow. Sadly all is not well .
When the shower works it works well. If you turn off the pump there is ample pressure to push water through the head almost to the point where I did wonder why i bothered with a pump at all. But, if we use the shower with the pump working and then the pump is inactive for more than a few minutes when you turn the shower back on nothing happens, no pump, no water pressure no nothing. Only when I give the pump a gentle shake will it kick into life.
I did read on one of these forums talk of a non return valve but failing that any ideas??

Ta.

 

[seco services]

even with pump not running are you not getting gravity pressure through the showerhead. ?
how is the hot plumbed into the cylinder ?
is no pressure on both hot/cold ?

 

[Willo64]

No, even with the pump electricity spur switched off there is nothing but a drip coming out of the shower head. This is true for both hot and cold. If you turn the shower temperature control to extremes you get nothing. The hot water feed is taken from the main hot water feed from the tank as close to the tank as I can get it and the cold is on an exclusive feed from the tank in the roof. As I say you could easily use the shower without a pump.
The output from the pump does run horizontal for a meter before the pipes rise to feed the shower head. I am wondering whether there is not enough pressure to overcome that but I feel like I am grasping at straws.
The fact that shaking the pump also makes tings work makes me feel that it is a pump problem or maybe even air?

Willo