I installed a radiant system with poured floors (no basement). customer calls, says he hears a loud squeaking noise accompanied by no heat and No pressure the water is not yet hooked up to house. I originally filled unit from neighbor's house. I asked him if he saw any water anywhere. he said no. (here would go pictures of sphincters slapping but I will spare you all.) I then find out that the drywall had just been finshed. I asked customer to call drywaller and ask him NICELY if they used water from boiler, turns out they used the boiler water for mixing mud and one of them was even DRINKING IT.