air stalling or better pump needed?

[Newtons Shed]

Got round to a wet run today using the new cheap china pump to pump from hlt to my MT through a herms, the pump was't powerful enough so I tried the solar project pump with the front off the Chinese one and this worked a little but then it than just stopped after switching it off for a while than turning back on it started to work again for a bit than same thing happened. As the silacone tubing with jubilee clips which I can't see any leaks on but when I blowed through to clear the water out I heard air blowing through near the soldered joint rducer going out of the terms so not sure if air is getting in to cause the pump to stall or the power supply which is an old model train track controller or the pump itself that is causing the flow to stop I just think if this is with just water what's it like with mashing so is it worth getting a better pump or is it my set up

 

[greenhouseuk]

Got round to a wet run today using the new cheap china pump to pump from hlt to my MT through a herms, the pump was't powerful enough so I tried the solar project pump with the front off the Chinese one and this worked a little but then it than just stopped after switching it off for a while than turning back on it started to work again for a bit than same thing happened. As the silacone tubing with jubilee clips which I can't see any leaks on but when I blowed through to clear the water out I heard air blowing through near the soldered joint rducer going out of the terms so not sure if air is getting in to cause the pump to stall or the power supply which is an old model train track controller or the pump itself that is causing the flow to stop I just think if this is with just water what's it like with mashing so is it worth getting a better pump or is it my set up

If you are talking about the WST china pump
http://www.ebay.co.uk/sch/i.html?_o...3.TR0.TRC0&_nkw=Wst+centrifugal+pump&_sacat=0
I have had a similar problem, it is certainly capable of driving my liquor up a 6 ft pipe and even through my plate chiller but really struggles if there is an air pocket in my pipe work between the kettle and pump. I am toying with the idea of having Some kind of a valve to resolve this...

 

[Newtons Shed]

Its the tan one which has 2m of head, I also found the herms coil had kinked and was leaking slightly. I think I need to re test it removing the herms coil as I think the kink is causing back pressure.