Teach me how this works... please.

[FixItPete]

I'm still learning, pardon me...

In the bottom of my U3 I have two holes... one is suction (where I now plug in my pool vac.) and one is, I assume, the "center drain"...

1) Is it safe to assume that the other one (non-suction) is for the center drain?
2) I recently bought an automatic vacuum plate (to switch between robot and skimmer) and it says to plug that second hole (non-suction)...

Can anyone confirm and please explain exactly what that second hole does? And what size the plug is? It appears threaded (?) (but not sure)...

Any other information would be a huge help.

Thanks
Pete

 

[Bama Rambler]

What is a "U3"? I assume it's a skimmer, but I don't want to guess. If it is it should be 1½" pipe threads.

 

[FixItPete]

Yes. A Skimmer... can you explain the rest?

 

[bignick]

If you search for "Sta-Rite U3", you can download an instruction sheet. In the diagrams, they show a generic plug, which leads me to believe it might be a universal part which a pool store might stock. In the instructions on how to vacuum, they mention a vacuum plate (which is also shown on the parts list).

The second hole is to prevent damage to your pump so that if your basket gets clogged, it can still pull water from your main drain.

 

[jblizzle]

The second hole is to prevent damage to your pump so that if your basket gets clogged, it can still pull water from your main drain.

For that to work you would need to have a diverter covering the holes under the basket.

The spaceship:

Or Twinkie:

 

[FixItPete]

Just printed the U-3 skimmer pdf... And, I'll say it, I'm baffled...

I do NOT have a "Equalizer Outlet" -- I do have the second hole (not plugged). I wonder if it is for the main drain???

I do NOT have a Check valve (spaceship or twinkie) of any kind. I have, from the top down:
The frame and grate kit (cover), the basket, and two holes... one that is suction and one that is "I don't know"

Anyone know the proper way to us the automatic skimmer plate. From the instructions it says to plug that second hole (non-suction)... I'm guessing you have to do that because I can't get ANY suction to the plate at this time (no plug)...

What say you?

 

[jblizzle]

Do you have any valves at the pump to select the floor drain? If not, then it is pretty safe to assume the other hole goes to the floor drain and you will have to plug it to be able to use the skimmer plate for the vacuum. If you do not, the pump is likely pulling some water from the floor instead of enough through the vacuum.

You may want to buy yourself one of the diverters (I have never seen the twinkie in person, so not sure what skimmer uses it).

EDIT: See Figure 5 in the PDF for you likely setup ... it also shows the spaceship (part #3).

 

[FixItPete]

Understood. Nope, no valves. Looks to be a 2" plug based on the part number (08655-0017) -- that should be a standard pipe thread, correct?

 

[Bama Rambler]

That's correct, it'll be standard pipe threads.