Pentair SuperFlo VS pump won't prime from any input source

[TANEAL1]

Two days ago, my pump was working fine with any of the 3 inputs selected: spa, vacuum cleaner or skimmer. Yesterday, I couldn't get the thing to prime from any of these sources. All I'm getting is a trickle of water into the pump basket. I'm getting suction at the pump basket, because the low pressure fogs the clear cover almost immediately; when I "unlock" this cover I can feel resistance - then there's a release and the water drains back into the filter basket.

The O-ring in the pump basket lid is in excellent condition. Basket is clean, fliter and cannister are clean, pump input line is tight with dope on the threads.

Between the pressure outlet side of the pump and the filter canister, I have a J-valve. One output is to the filter canister, and the other is a drain line to the street to lower the water level in the pool. With this valve cracked on the drain side, I should be allowing any air to escape from within the pump.

Today, I tried filling the pipe from the Skimmer to the pump. It shares a J-valve with the vac, so I screwed a threaded plug into the pool vac intake so the water wouldn't leak out from that pipe. Next I removed the J-valve cover and filled the pipes to the skimmer and vac with the garden hose. This also filled the pump basket. I replaced the J-valve cover and the pump basket cover.

The water sucked the pipe dry quite nicely, and then only produced a trickle into the basket.

Any ideas are GREATLY appreciated!

Tom

 

[mas985]

Did you check the impeller inlet for debris? A clogged impeller will have a problem priming.

 

[TANEAL1]

Did you check the impeller inlet for debris? A clogged impeller will have a problem priming.

Thanks Mark,

I did - it's clean.

Tom

 

[mas985]

What speed are you using to prime? If less than full speed, try full speed.

Does the filter pressure have any reading while priming?

Did you recently vacuum up a large amount of debris from the pool?

You may need to disassembly the wet end so you can directly inspect the impeller. Not all debris can be removed from the inlet side.

 

[TANEAL1]

What speed are you using to prime? If less than full speed, try full speed.

Does the filter pressure have any reading while priming?

Did you recently vacuum up a large amount of debris from the pool?

You may need to disassembly the wet end so you can directly inspect the impeller. Not all debris can be removed from the inlet side.

Prime - full 3450 RPM

Filter Press = 0 PSI

I did vacuum up quite a bit of green algae, but no solid debris. Could that foul the impeller?

Tom

 

[TANEAL1]

I undid the 4 bolts holding the strainer/valute to the rear pump assembly and separated the two halves. I removed 3 screws and the diffuser.

At this point I discovered a bright shiny hex head screw, about 1 1/8" in length just sitting next to the impeller. The screw that is supposed to hold the impeller onto the shaft is NOT shown in place in the pump diagram, nor is it physically described. I couldn't see this screw, so I used an Allan Wrench to prevent the shaft from turning and unscrewed the impeller. It came off easily. Assuming it was a left-hand thread I tried installing this screw into the motor shaft. It was a little tight, but went in, so that must be where it belongs. I can't imagine how it fell out unless it was simply never tightened.

Prior to this disassembly the motor was spinning freely. There are no marks on the impeller and there was no trapped debris - OTHER than this screw. Right now I'm taking a break from the heat outside, and will reassemble the pump soon.

Obviously, it was good to find the screw before it caused any damage, but I doubt it impeded the water flow enough to cause my priming problem, but we'll see...

Thanks again for your comments,

Tom