pump won't prime

by Bruce
(Baltimore, MD)

We have had this pump, which is connected to a biological filter and UV filter, for about 4 years. It has always been difficult to prime each spring, requiring running lots of water into the pump, but this year I have nearly filled the pond to overflowing and can't get it to prime. Any ideas?

Doug says it sounds as if you have a bad impeller. If you can have it serviced or find parts - this would be the "cure" - but that's only an educated guess.

That's always assuming there are no air blocks in your plumbing that stop the pump from picking up water. If you put it at the bottom of the pond with the inlet open - and it still won't prime - then you're looking at impeller. If it will prime and pump easily from there you have a plumbing issue.