Pump losing prime?

I've used my March H315HF for 2 brew sessions. Both time when pumping hot wort (cold clean water seems to work fine) the pump would make an awful screeching sound and stop pumping, the fan is still running when this happens. It seems seized. I restart the pump and it works again. It does this around three times before it works flawlessly. Is the loud screech common? Am I just losing prime?

Thanks,
Landon

How do you have the input and output oriented? The noise could be caused by cavitation. If the inlet is higher than the outlet and air pocket could develop in the pump head. It's best to have the inlet at the bottom so air bubbles are ejected out of the pump head.

Look for posts from WalterAtMarchPumps.

It's vertical and the output is on top.

Landon, just replied to your PM. Shoot me a pic of your setup if you can and i will see if there's anything that can be changed to help.
Most times that "screeching" noise you hear is the impeller bouncing/vibrating around on the shaft it sits on. And its usually due to no liquid between the two. Most times it due to a big air pocket getting sucked into the pump for some reason. Either you have a bad fitting on the plumbing that allows air to get it....you are very near boiling and are starting to just get bubbles come off the floor of the kettle and get sucked into the pump. Or there could have been an air bubble trapped either in the pump head at startup or in the line feeding the pump and it has worked its way into the pump now.
Most times people call me about that screeching noise when they first buy a new pump and want to test it by plugging it into the wall and make sure it runs without any liquid in it!

-Walter

I'd bet that most of the time with boiling wort issues you are getting bubbles/air at the pick up tube point. I've got 2 March pumps & 1 Chugger and they all handle boiling liquids without issue.