i am using CM3-5PM1. When switch on the water tap, a weak water pressure come out for 1sec before pump kick-in. It seems like water pipe is not holding a constant pressure. I am using it for 1year, no water leaking and pump is working good. During idling, the pump is just in standby mode, never encounter any crazy symptom on the pump itself. Does it look normal for those who also using a same model with me ?

So you have a same situation here ?