Review on Circulation pump Grundfos UP 15-14 B PM (7 W) by Stanislaw Banasiuk ᠌

I installed hot water circulation in a 2-storey building. The previous Chinese pump worked for a little over a year. After installation, there was a slight rustle in the operation of the pump. I was even a little upset, I thought I was also unlucky and got a defective pump. But literally, after a couple of minutes, everything calmed down. I even wondered if he had died with me). But it turned out that silence is the normal mode of operation of the pump. Apparently at first he drove the "airy" water. I hope for a long and trouble-free operation.