Blow it and seal the line. The valve will seal on one side and the trap will seal the other. As long as the water in the line is below the frost line, you'll be fine. You will see some bubbles for a minute or so after sealing, but not a lot.

Scott

Forgive my ignorance, but how do I blow it and seal the line? Water is just flowing down the line into the pump basket. There is a valve of course so I'm able to close it and stop the flow, but I assume I need to get the water out of the exposed pvc at the pad.

I tried blowing it back up, hoping that I would be able to push the water up and over the trap to stop the siphon affect, but I wasn't able to.

1) All valves to the pump (both sides) to the closed position.

2) Remove the pump's drain plugs. If the filter isn't drained, do so also.

3) Blower (5 HP shop vac works well) to the pump's suction side port and open the drain valve.

4) When air is blowing out the drain in the pool, reseal the drain valve to lock the air in.

Scott

That's exactly what I tried to do, but I never was able to get air to the drain. I was having a hard time getting a good air tight seal with my blower at the pumps suction port though. I will try again.

Thanks so much Scott. You've been a tremendous help.

One other quick question/confirmation. I'm assuming my skimmers will need to be completely drained, blown out, then plugged. Because any water left, even below frost line, will simply drain down to the exposed pipe at the pad. Correct?

It is much easier if you lower the water level below the returns first. Then the lines can be blown out without fighting as much pressure. This should be below the pad level as well so water will not rush out of the pump and/or refill in the lines. There is a proceedure in the link below that might be helpful.

Here is a link that might be useful: Closing an inground pool

I don't/won't drain that much unless it's for dilution purposes. An automatic step pump keeps the tile line free of water-ice related expansion stresses.

A blow through gizmo or similar device will protect the skimmer and seal the line water tight.

if you are using a 3HP shop vac, it's hose is likely to big to fit on the pump's suction port. H-D and Lowes have adapters that will likely fit in the port so you can get a better seal. If not there, then it's off the the plumbing department for a suitable rubber adapter (1.5" to 2" usually works). This should allow enough air to be pushed below the frost line, even if it doesn't quite make to the drain.

Scott