Hi Guys,

I've got a developer-supplied water pressure system modeled Grundfos CM-PT installed on a 3-storey link house. Just moved in, it was working fine for a month, and now the pump runs continuously without stopping. Sometimes the low rumbling sound also accompanied by groaning sound. There's a switch that I used to turned it on 24/7, but now due to the incessant sounds from the pump, I had to turn it off whenever water is not used.

Is it normal for a water pump to run continuously...? Previously it only runs intermittently when water is used especially on top floors.