The circulation pump has no flow

Just by looking at your question, it’s clear that you’ve already solved this problem. Could you share it with everyone as well? Let’s all learn from it and make progress together!

No, it switched back again. The master asked me to come back and think it over. I’ll go back and continue cutting tomorrow

There is air in the suction line or pump, and it needs to be removed. There was air leakage in the inhalation pipeline; the leak was identified and repaired. The valve on the intake line or exhaust line is closed; it is necessary to open the relevant valve. The suction height is too high; recalculate the installation height. The inhalation tube is too small or blocked. Adjust the diameter of the inlet pipe. The impeller is damaged, resulting in insufficient cutting of the medium being pumped. The impeller needs to be replaced. The impeller flow channel is blocked. It is necessary to remove foreign objects from the flow channel. The impeller speed is insufficient; identify the causes of this low speed, such as an inappropriate motor match, and make adjustments accordingly. The impeller direction is incorrect; adjust the rotation direction of the motor or prime mover again. The head of the device is higher than that of the pump, so the selection needs to be recalculated.