Winterizing main drain with just anti freeze?

Esand323

Well-known member
Aug 6, 2018
110
Indianapolis
Hi all,

I'm trying to come up with a way to winterize my main drain. Long story short, we can't air lock the typical way. Last year, I was brushing the pool and bumped the main drain. This caused a leak. It was determined that the wrong screws were used for the Hayward main drain. I was able to get the correct screws and this fixed the leak. Then we paid for a company to close the pool a couple months later. They used an air compressor to blow out the main drain line. This caused the leak to occur again in the same spot and we were losing 4" a day. We couldn't get the leak fixed properly as it appears the gasket is shot, so we had to temporarily fix the leak with a sealant. The sealant has held up for the past year. We'll eventually get a new liner put in and have the main drain properly installed.

My plan was to use a shop vac to lightly blow out the line, but I'm expecting this won't work all too well as it's not strong enough. I also don't want it to be too strong and cause a leak again. Then I was planning to plug the main drain line with a rubber plug and dump a few gallons of anti freeze in the line.

Any better Ideas? I'm aware that repairing the main drain properly so that the line can be properly cleared would be ideal, but it's not going to happen this year.

Thanks in advance.
 

Texas Splash

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Jun 22, 2014
37,939
Texas, San Antonio/Marion, South-Central Area
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Since pushing water out is not a viable option this year due to the gasket damage, I wonder if you did plug the drain, if you could get enough suction to pull "some" water out? I wouldn't expect you to get it all, but perhaps enough to create a bit of an air gap above the frost line and perhaps allow you to get antifreeze to drop to the bottom better? @ajw22 your thoughts?
 

ajw22

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Jul 21, 2013
35,313
Northern NJ
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Stuff foam rope down the main drain line as far as you can get it. That will create an expansion area for any ice to expand into and should not crack the pipe.
 

Esand323

Well-known member
Aug 6, 2018
110
Indianapolis
Thanks for the help! I didn't think of using a foam rope before. But that makes sense!

I was thinking about it today and came up with an idea. I'm curious to know what you think! I was going to purchase a water transfer pump, something like this: 1/10 HP Transfer Pump 320 GPH. I could plug the main drain and stick a hose down the pipe. Then use this water transfer pump to pump all the water out.

Thanks again!
 

IsThisWhereIPutMyName?

Active member
Apr 21, 2016
39
Massachusetts
I have an above ground Kayak pool with a mini 5.5’ deep end. I add RV antifreeze to the main drain line and tie off the line at the top of the pool wall. I use 1 gallon for about 12’ of 1.5” flexible PVC. Antifreeze sinks so it is stays at the bottom of the pool in the drain and the diluted mixture in the rest of the pipe keeps it from freezing all winter. Whatever you choose to do otherwise, I would add a liberal amount of antifreeze to the line.
 
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