We have had a groaning noise like air in the pipes for over a year. It's very sporadic. It can happen with both cold and/or hot water. It can happen when upstairs or downstairs water is on. We are on a well and had the well pump guy come. of course couldn't get it to make the sound while he was here. He did note low pressure on the tank and recharged it. We had the sound after that and it extended out longer (with the more pressure now behind it). Had the plumber come but of course couldn't get it to make the sound while she was here. The part making the noise seems to be the relay. But what is causing the relay to make the noise? We replaced the relay, and the breaker. The tube going to the relay was clogged. (now unclogged) Our plumber is mystified as well....She suggested this forum.
