Bro, the grundfos pump CH2-50PC model that I bought for the house is superbly fast man. I Need to turn the tap only little bit, otherwise the water comes splashing like pressure jet. I have a question. The pump operates like every 1/2 hour or so (for a about 2-3 seconds) even if no tap is turned on. Is this the case? I hear the pump noise at night time even if no one is using the loo.