Plumbing/Pump question for all the experts.

[lovingHDTV]

Background:
1. My pump vapor locks anytime the pool goes low of water (expected), but starting it back up is quite the pain.
2. My pool is about 8 feet higher than my pump.
3. prior to vapor lock, if I remove my pump basket lid, water will free flow from the pool to the pump.
4. after vapor lock, it will not flow from pool to pump any longer.

To get my pump to restart after a vapor lock. I have to take a hose, with the black rubber thing that expands when water flows through it, and fill the pool return line with water. I put it in via the pump basket. When I do this I see lots of bubbles comes from the return back into the pool. After all bubbles are gone I can turn off my return valve, to hold the water, put on the pump strainer lid, turn on valve and go. The pump will then work.

What I can't understand is why wouldn't the water just flow downhill through the pipe and push the air in the return out through the pump? It does this when it is full of water. Its almost as if there is a point in my return line that goes higher than the pool level? If this were the case I could understand the issues but my pool is above my pump.

Anyone out there have any idea what could explain my vapor lock issues? I"m not hopefully, but I do like to be surprised

As an aside, my spa returns have the same problem and the spa is a couple feet higher than my pool.

thanks,
dave

 

[duraleigh]

after vapor lock, it will not flow from pool to pump any longer.

Hey, HD,

This part has me a little confused. Are you saying that if the pump loses prime (vapor locks), that you can remove the lid to the pump strainer basket and no water comes out?

If there's water in the pool (covering the skimmer intake) and you (essentially) open the bottom of a pipe connected to the pool, I can't see anyway for it (the pump strainer basket) not to fill with pool water.

 

[JohnT]

Have you tried pressing down on the multiport handle or setting it to recirculate?

 

[lovingHDTV]

after vapor lock, it will not flow from pool to pump any longer.

Hey, HD,

This part has me a little confused. Are you saying that if the pump loses prime (vapor locks), that you can remove the lid to the pump strainer basket and no water comes out?

If there's water in the pool (covering the skimmer intake) and you (essentially) open the bottom of a pipe connected to the pool, I can't see anyway for it (the pump strainer basket) not to fill with pool water.

Yes this is what I'm saying.

 

[lovingHDTV]

Have you tried pressing down on the multiport handle or setting it to recirculate?

I did press down on the multiport handle. Sometimes it causes bubbles to come out, but today it did nothing. I have not tired to turn it to recirculate before.

I'll try that next time.

It got vapor locked this time because the kids left a plastic bags outside after shucking the corn for dinner. This bag then got blown into the pool and got captured by the skimmer basket blocking all water.

dave

 

[Bama Rambler]

The only explanation I have is that there has to be a high point in the suction (Skimmer) line where the piping is higher than the water level. Prior to your "vapor lock" (not really what this is) there's a syphon effect going on. Once you break suction to the pump and the suction line gets air in it it occupies the highest point and the water won't flow over it. A high point in the return line would have nothing to do with the water not flowing out of your pump strainer vessel when you open it.

 

[duraleigh]

Where's the bag now? Is it in the pipe still?

Unless there is a valve closed or some blockage, water must flow from the pool to the pump with the pump lid removed. I am apparently missing part of this.

 

[X-PertPool]

The only explanation I have is that there has to be a high point in the suction (Skimmer) line where the piping is higher than the water level. Prior to your "vapor lock" (not really what this is) there's a syphon effect going on. Once you break suction to the pump and the suction line gets air in it it occupies the highest point and the water won't flow over it. A high point in the return line would have nothing to do with the water not flowing out of your pump strainer vessel when you open it.

I think you are correct here, I had a customer where the entire pool system was below water level and it was difficult to get a prime in the system after opening. We forced water into the skimmer line with a pump and once the air gap was out of the line it began to flow as expected for having the system below the pool.

 

[duraleigh]

Yeah, I can see, if the system is closed to the atmosphere, that once unprimed, it would be hard to prime again......provided you kept the system sealed so the "bubble of air" couldn't escape in either direction.

But, OP is saying that pump basket will not fill even when he removes the lid. He is also saying the pool is above the pump and the skimmer line goes straight to the pump. (I think there may be a shut-off on this suction line)

When you crack that seal by removing the pump basket lid, the water in the pool has a straight path down the pipe and into the pump basket.....there's no way it cannot fill (and overflow) that pump basket.

I'm not the sharpest knife in the drawer but something is missing here. Water flows downhill (at least here in NC :lol: ) and that water has to flow down from the skimmer and out the top of the basket.

 

[lovingHDTV]

I got the bag out, it was stuck in the skimmer basket.

Sounds like everyone here agrees that the returns must go above the pool level somewhere and that would explain the behaviors. I'll have to take a laser level out and see where the ground level is higher than the water level. Maybe it is and I'm just not seeing it with my bare eye.

dave

 

[Ohm_Boy]

Yeah, sure sounds like either the pipe is above water level, or there is something in the pipe.

Just for bonus points, let me relate a story once told to me by a landlord...
A tenant had a problem with a plugged toilet. Every attempt to snake it indicated that the entire drain path was clear, but when water was sent down the line, it overflowed. Ultimately, after replacing the toilet and breaking the old one open with a sledgehammer, a coffee can lid was found in the "S" turns of the bowl drain. The snake flipped it sideways and went right by it, but water made it flap shut like a check valve.

Obstructions can be tricky.