pumping probs

[cam]

HI all my first time on here be gentile. I have a pumped shower hot & cold. all pipe work as per pump manufacturers instructions for a neg head pump. From the pump the pipe work runs up into the loft across loft and down to mixer after using shower the pump stops and starts every 5 mins untill you turn off the pump do i need air bleeds in the loft as this is the highest point in pipe runs thanks martin

 

[Plumbstar Tom]

popping a non retun valves on the outlets of the pump should cure this

 

[cam]

thanks tom, the pump i have fitted has its own non return valve, im on the second pump (first went back)

 

[radswilldo]

Take it you've got auto air vents at highest point. Sounds like a small leak down stream of pump