Pump water level slowly dropping?

[BenjaminLucas]

I replaced an old Pentair Whisperflo with a VS Intelliflo yesterday. I started with an 18 hour cycle at 750 rpm as a starting point and checked the pump at about 6 hours in yesterday afternoon. The water started flush with the lid of the basket and at the 6 hour mark it was down maybe a few inches. At about the 10 hour mark it was down to the top of the basket. I shut the pump off at that omegle discord xender point because it was getting dark and I was worried about the pump losing prime overnight and running dry for hours. The other threads I've found here suggested maybe there was a suction side leak. However, I ran the pump at full RPM for about 10 seconds and the water level came back to the top of the basket. The pump sat overnight for about 10 hours and this morning the water level was still completely full. Wouldn't a suction side leak cause the water level to drop with the pump completely off? If the pump loses prime in the middle of a cycle, is it smart enough to re-prime itself?

Thanks in advance.

 

[ajw22]

Welcome to TFP.

The pump basket not being full when the pump running at a low rpm is a normal behavior. The low rpm just is not sucking enough water in to keep the basket full. 750 rpm is very low speed. Most folks run their pump at 1200 rpm or higher.

@Jimrahbe do you know what the Intelliflo will do if it loses prime at a very low pump speed?

 

[bligh]

I installed a new Hayward VSP last year and had the same problem. I went so far as to replace one suction line ( it wasn't working anyway). Upon restarting the system this year I saw that the collecting air in the basket was still their but much less. I was told by my Hayward guy that all VSP will do this set at very low speeds. Perhaps it's not so much s suction leak as it is air from cavitation. Today I run mine at 1200 rpm (98 watts) and a very small amount of air collects, not enuf to lose prime. My motor is programmable so I can set the rpm very low for a hour or two if I wanted to and then say a higher rpm to clear the air if it becomes a problem. So far so good. Best of luck with yours.