Eheim 1250 cracked impeller?

[georgec]

I was doing my water change today and when I restarted my return pump, it didn't run. It looks like the impeller magnet is cracked end to end. It's a 5+ year old eheim 1250. Never had a problem with it. Has anyone had this happen to them before? Luckily I had a mag 3 sitting around to backup.

Before I order a replacement impeller, is there anything else I should consider that may have caused the impeller to crack?

 

[rygh]

It has happened to me on on a couple of pumps and powerheads. Various brands.

It seems to be inversely related to the maintenance.
I think if they jamb due to calcium buildup, they get hot, and that helps them crack.

 

[georgec]

I cleaned out the pump and am doing a vinegar bath soak while waiting for the replacement part. Forgot how loud the mag pumps are compared to the eheims.