+1. At near 'freezing' temps, it will take a long time to freeze, if it does at all. But an ounce of prevention whoops a pound of cure and whatnot. 
Freeze Preparations (TX, LA, GA, AL, FL, etc)
- Thread starter Birdman75
- Start date
I'm watching it now. There's some nonfrozen water sitting on the top of a check valve. If it starts to freeze, then I'll drain. Hourly forecast shows 32-33 from 1-4p today. If the power isn't back at 4p, I'll drain everything for the night.
Good article for reference. I do agree with @Newdude - an ounce of prevention.........
Physics of Freezing and Freeze Protection
The Physics of Freezing and Freeze Protection
I drained everything but the cartridge filter. The bottom drain won't come off. I tried to heat it. As of now, it's probably half full.
- Jun 22, 2014
- 52,034
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
That could be an issue. It would be easy to assume water freezing inside should simply rise upwards, and it might a bit. But I wonder if it could also develop a quick ice shelf and begin to swell in the bottom damaging that area and/or the parts inside. If you can't get the drain cap off, have you considered removing the top half of the filter and using a Shopvac to remove as much water from inside as possible?
I just got the whole bulkhead off. Everything drained out. The drain cap is stuck. I'll put it in a vice and warm it up when the power comes back on.
I have a relative with a Jandy Cartridge filter. It has a nut similar to a union on it that allows a plug to be removed. Similar to what they use on the Jandy SWCG to hold the sensor in place. Some have put a ball valve to facilitate draining. See picture.
Good idea. I'll explore that option in a couple of months. It will make cleaning the filter easier as well.