Pump, prime, and waterfall in the skimmer

[SBall]

Dual speed whisperflo and a cartridge filter, and equipment pad above the water line. I have skimmer followed by pentair check valve (vertical), union, and pump. The check valve and union are within 24" of the pump. No other check valves in the system. When I start it in low speed, the pump basket gets partially full, and some water comes out of the returns in the pool. There is a several minute "cycle" which seems to culminate in a waterfall in the skimmer.

I got it started in high speed, and managed to get it primed, bled the air out of the cartridge filter, turned it down to low speed, and it ran great for a couple of hours. Not a single bubble in the pump basket, no air bubbles from the pool returns, and very nice flow out of the returns.

After a couple hours, I shut the pump off, pump basket stayed full, did not hear sounds of anything draining. Immediately turned pump on with low speed, and the pump dumped the entire basket into the filter, dropped down to about 1/3 full, and then proceeded to return to the whole waterfall cycle as described above.

My gut feeling is that the water in the return line below the check valve drained back into the pool...so essentially my check valve did not act like a "thumb on top of a straw". Rather, the check valve/pump hold water, the line drained, and when I restart pump, it sucks in a big gulp of air from just below the check valve.

I have to assume that my check valve is pulling air in through the screwed on cover, or possibly the union. Those are my best guesses. Any other suggestions?

 

[SBall]

System off. I open the air bleeder on top of the cartridge filter, turn on pump at high speed, pump basket fills quickly to the clear cover and air roars out of the bleeder. When water comes out of the bleeder, I shut it, and immediately, the pump basket entirely discharges. Literally as soon as I shut the bleeder, pump basket empties and pump no longer primed.

 

[Jimrahbe]

s,

Normally, a pump cannot drain a skimmer and cause a "waterfall" unless not enough water is coming into the skimmer. I suspect your problem is that your weir door is stuck in the up position.

When you release air out of the filter, you don't stop until water starts to come out of the air relief valve.

Unless your pump is way above the pool, you should not even need a check valve, so something is wrong. Your pump should prime in less than a minute.

Thanks,

Jim R.

 

[mknauss]

As everything works with air bleeder open, would that imply you have restriction on the return side somewhere? Such as a dirty filter, valve closed, etc?

 

[sktn77a]

The flow into your skimmer on low speed may be insufficient to pull the weir down (may be stuck or stiff), whereas on high speed it does. Try putting something on the weir door to keep it down (without blocking off flow) and see if it then works on low speed.

 

[SBall]

So it appears to be at least partially the weir door, but I also think that it was made even worse by the check valve. I pulled the clear cover on the check valve, removed the pin/spring/flapper, and replaced it, and then stuck a pool noodle in the skimmer forcing the door open. I think that the weir door may have been partially sticking, and when it waterfalled and I closed the valve on the filter the pressure spike actually forced water the wrong way and shut the check valve, which just made things worse. In any case, I now have a nice, shiny, expensive see through "coupling" and am going to have to see where the weir is sticking.