Does this sound like I need a new pump??

[TomF]

Hi, checked the impeller and it was clean...any other thoughts?
Thanks,
Tom

[waste]

Tom, a lonely thought, putting a 'backflow prevention valve' or check valve on the suction line would prevent the re-priming problem. If you have valves on the suction lines, close them before opening the pump lid, of course you'll have to open the valves again when restrting the pump - also, only open one line when restarting the pump, then crack the other valve (just enough to draw the air out of the other line without loosing prime) and open it when you are drawing only water.

[Poconos]

Tom,
That 4' elevation is certainly not helping the problem but since the system was working for several seasons, says something has changed. My best guess is you have a very small air leak in the suction side and because of the additional suction required to handle the 4' rise, a small leak can definitely cause the problem you are seeing. Another best guess is the leak would be at the highest point, the pump, because this is the point of maximum suction or vacuum. Don't know what your system looks like but here are my guesses and remember, we're talking a very small air leak::
--Pump basket lid. Give the gasket and seating channels a good visual and don't spare the silicone grease when putting it back together.
-- drain plug(s)
-- Any pipes with hose clamps on the suction side? Those barbed fittings can leak easily.
There is another highly unlikely possibility and that is the clearance between the impeller and the pump chamber. I don't know what this clearance typically is but I suspect on the order of mils. This lets the pump creat enough of a vacuum when wet to be 'self priming'. If this clearance open up just a little, then there won't be enough suction to sustain the 4' water column. If something got past the pump basket and damaged the impeller edges or the chamber then it could be a problem. Again , highly unlikely. Only way I know to find out if to disassemble and inspect.
Gotta run.
Best I can think of now.
Al