Grundfos Bossert pump trouble shooting!?

[ballinacian]

Apologies for my spelling of booster!
Hi, Its my first time posting here, lots of you guys know your pumps!!
I have a grunfos Mq booster pump boosting my domestic cold water into the house. Recently it has started turning its self on and off intermitantly,on for 15 seconds then off for 1 minute.
I have checked for obvious above ground leeks. Could any of you guys be able to tell me what coul dbe the problem.
Thanks in advance!

 

[kimbo]

This is operated by a reed ditch which detects water movement in the pipe something in the house is letting water by. It could be a ballvalve. Isolate piper to find out which section it is in.

 

[ballinacian]

Is it a switch that senses movent rather than a pressure drop? I must re check everything, just hoping its not a below ground leak, Thanks for your opinion!

 

[kimbo]

A pressure drop. can do it