Pipe freezing question

[wayner]

I live in Toronto. I don't open and close my pool, I have a service do that but I do all of my other maintenance. When they winterize they drain water below the jets and put plugs in on the jets and skimmer - I think.

But my pool has two bottom drains. What happens to the water from the bottom drains and the pipes connected to them? You can't blow out the water since it would keep coming from the pool and I don't think the bottom drains get plugged. Why doesn't the water in the pumps connected to the bottom drains freeze and crack the pipes? Or is this far enough underground that it won't freeze?

 

[Newdude]

Think of the finger on a straw trick. A valve needs closing under pressure and it airlocks to keep water out. The horizontal pipe under the pool to the drains will glug glug full again but as soon as the pipe turns upward, no more water will enter. It's 8 ft down or so and well below the frost line.

Without a closed valve or plug, the water height in the pip will be at the pool level and freeze by the pad somewhere. Mine go 4 ft down at the pad (not enough for you) then go the rest of the way down at the pool wall.

 

[ajw22]

You only need to get the water in pipes down below the frost line for your location...

 

[Newdude]

Basic sketch but you get the idea. The pink pipe will fill again but the green will remain empty if the pipe was closed under pressure.

 

[wayner]

Ok thanks, I was assuming that the water would rise back up to the water line in the pool, which I assume is the green horizontal line in your sketch. And that could creep up over the winter as the pool refills with water from rain and snow.

 

[ajw22]

Ok thanks, I was assuming that the water would rise back up to the water line in the pool, which I assume is the green horizontal line in your sketch. And that could creep up over the winter as the pool refills with water from rain and snow.

Only if your valve is bad and not holding the air lock pressure to keep the water from rising in the pipe.