I recently added radiant flooring under my kitchen. All I did was remove a hot water baseboard and added this in the same loop. It added 200 feet of pipe to zone 1. I used the vapor barrier pex tubing. Now not right away but two weeks later I had my furnace cleaned. A week after I started hearing a low frequency whistle coming from the first baseboard. I thought maybe I had air in system. I removed baseboard added bleeder elbows. I noticed baseboard was bent figuring air was getting caught I replace baseboard with one I had. The noise stopped. Two days later it has returned. Is it possible my circulator is not strong enough to push all that water? ALso my circulator ran dry for about a day when I did my floor heat. I turned on thermostat to get circulator to run to check for leaks. I closed shut off and forgot about circulator. The next day I was in the cellar and noticed it still running with no water. I am clueless now any help would be appreciated.