Grundfos Recirculation Pump Noise.
I have a Grundfos UP 15-18 B5/LC 1/25 HP recirculation pump at my residence and it started making a very loud, high pitched scream. I unplugged it, and the next day I plugged it back into the AC and the noise has now stopped.
What could have made this noise, and is the pump going bad? It has been in use for only 1.5 years.