We bought a new 3 levels house and the utility is at the basement. The water pressure is not that strong, but since we are at the the top of the moutain, we didn't care that much. Recently if we flush the toilet or use the faucet upstairs in our master bathroom, we can hear clunking coming from within the wall. It will do it for a few clunks only. On the upstairs faucet, if we turn up the volume, the clunking noise will get louder. But it doesn't clunk when we use the shower or bath at upstairs, weird?
Also if we don't consume water, most of the time it will clunk every 3-5 minutes. Other faucets or toilets are fine at the ground level or at the basement. please help!!