I winterized my pool this weekend. No problem with the skimmers or the one return. Wasn't able to get any air out of the main drains with either my air compressor or vacuum. Now, my question. All of my lines are at minimum 28" below ground level and then enter my pool house which has never been below freezing during last winter. Do I have any worries with freeze protection?

Just for confirmation, the pictures below are all of my lines going into the pool house. The 2nd picture provides a good view of all the pool lines going into the pool house. The ground level is shown in the 1st picture. And for reference, the top of the top treated 2x10 is ground level from the other picture.

How is it that a compressor couldn't blow the drain?

Scott

Along those lines, I blew out my neighbors pool this year with my compressor. His main drain is 8 feet down and I got it to blow at 8 psi.

OK, here is what I did. I hooked up a line to the drain in the pump. I closed the filter by putting it on the CLOSED indicator and started the compressor. That would mean it was blowing out all the lines in each direction. Without disconnecting the return line leaving the pump, not sure how to address the main drain alone. But my question, would it really matter given my setup. I think not. The level of my water is 18" below deck so anywhere other than in the pool house, my lines are 28" below ground level for the main drain.

It's possible if the MPV is leaking a bit and the compressor doesn't shoot off a huge volume of air you could be losing air out the backwash.

I think you'll be fine in MD. At 28", it shouldnt be an issue.

FWIW, I blow the lines with the multiport on recirculate.

I might try it again just to be sure. Practice makes perfect. I wonder if I ran the compressor long enough? I am a visual guy and wondered right away why I wasn't seeing any bubbles. Didn't look too closely and then figured it just wasn't working. I'll put the multiport on recirculate and give it a whirl in 2 weeks. I don't believe it's a problem, because I've built up completely around my pool house so I don't think there is any way that I'm near a frost line, but I'd much rather be safer. Thanks all.

It's not really a question of how long you run your compressor after you open the valve. I do this every year with a compressor and air is creating waves in the pool seconds after I open the valve. You want the compressor to have filled its tank to full pressure and shut off. You want to blow one line at a time. Let the compressor recover and shut off after each line. I blow return on Recirc. and main drain and skimmers on Closed. To blow the main drain, you need to close skimmer lines (and any other suction lines) with their valves or plug them at the pool if your setup won't do that. I use a painting regulator set at about 12 psi and it is plenty. But you want your reserve tank at 90 psi or whatever the max your compressor puts out so that you have plenty of reserve air. Don't just throttle the compressor down to 12 psi.