We had a tankless water heater installed (in the basement) about two years ago. Over the past six months, it's been making a horrible sound whenever you turn the hotwater on. At first it only happened when you turned on certain faucets (like the kitchen faucet). Now, no matter where you are in the house, if you open the hot water spigot, you hear a loud rattling/banging sound.
It usually subsides after a few seconds, however, it is really troublesome to feel and hear...if even for a short period of time.
I'm sure it's not suppose to do that. Can anyone offer any suggestions on what we can do to stop this from happening? I'm fearful that it could be leading to a more significant problem, down the line.
BTW: My husband did try 'bleeding' the lines before and he's already checked all of the joints for 'tightness'.