Air sucking into pump...

[taekwondodo]

on the suction side...

Pump - TWV (three way valve (to pump, from spa floor, from pool skimmers). A couple of 90o elbows that seem very air-tight, and then 2" pipe into the ground.

TWV Direction from Spa floor. Zero air coming in from that direction - pump basket removes all air.

TWV Direction from Pool Skimmers (skimmers have plenty of water) - pump basket collects air. Not enough to break suction on the pump, but there's still quite a bit of air coming into the basket and making it back to the return jets.

The only place I can imagine air coming in would be a leak somewhere in the 2" PVC, but the pool doesn't lose water when the pump is off, and there's no dirt getting sucked into the filter (just cleaned the filter a few days ago - lots of dead algae, but no dirt...).

(edit - oh yeah, and when I have the vacuum hose plugged into one of the skimmers (and plug the other skimmer w/a tennis ball), so much air gets into the pump, vacuuming becomes impossible)

(another edit - brand new o-ring on the pump lid...)

Ideas? Things I should be looking for?

Thanks,

- Jeff

 

[JohnT]

Do the weirs in the skimmers move freely?

Is the run from the spa to the pump much shorter than the run from the skimmers to the pump?
If it is, the extra suction required to move the water from the pool could cause a valve, cracked pipe or the strainer basket lid to leak only when the valve is set to pull from the skimmers.

Do you vacuum with the skimmer basket in place?

 

[duraleigh]

what does your filter guage do when you switch between the two sources?

 

[taekwondodo]

Will have to look at the filter gage on Monday.

Spa is MUCH further (60'?) than the skimmers (20').

Do you vacuum with the skimmer basket in place?

What am I missing here (don't understand).

Two skimmers, one gets the vacuum hose, the other a tennis ball.

Also, the skimmers are working correctly (door/weir).

 

[JohnT]

Will have to look at the filter gage on Monday.

Spa is MUCH further (60'?) than the skimmers (20').

Do you vacuum with the skimmer basket in place?

What am I missing here (don't understand).

Two skimmers, one gets the vacuum hose, the other a tennis ball.

Also, the skimmers are working correctly (door/weir).

If you vacuum by plugging the hose directly into the skimmer opening vs. using a skimmer plate and leaving the basket in place, you could have a clog in the line.

 

[taekwondodo]

OK,

I verified that there is no clog between the skimmer and the pump - I tied a string to a golf-ball-sized whiffle ball and dropped it into the skimmer and it went all of the way to the pump (and was able to pull it back through to the skimmer.

I also put some "high-tec" sealant (play dough) around the PVC joints at "B" (below picture) and as long as the JVA was "on" to the pool, it sucked air. When it is "on" to the spa, the basket's air vanishes quickly. When I switch it back to the pool, I can see air coming into the pump from the direction of the inlet (PVC connection to the pump).

The last thing I can think of, is that for some reason air might be coming in the JVA valve when pointed to the pool, but not the spa? Seems unlikely... but that's the last place that I can think of short of a pipe-break underneath the deck.