ustcer90:
I take my Polaris 360 out of the pool when I'm not using it and store it in a shed.
Not sure where you live, but here in DFW I keep the pool operational year-round even though it's too cold to swim in for 4-5 months out of the year. During the winter, I manually fish out whatever falls to the bottom and use the Polaris only if absolutely necessary. The first year I was in this house, I left it in the pool all winter based on advice of friends/co-workers. Around mid-late February of that year, it started malfunctioning. Part of the cause was hoses and seals and part of it was devices within the unit itself. Pool store near me (which is rather reputable compared to some of the pool store stories others have posted) mentioned that the colder water tends to make parts more brittle and susceptible to breakage. That seems to have merit in my case. This past winter, I used it only 2-3 times during the off season with no problems and avoided the previous year's hefty repair bill. So that advice seems to have worked well for me.
One other related bit of advice: The bag is much easier to empty if you let it dry completely first. On mine, I disconnect the bag from the unit, store the unit in the shed, and leave the bag in the sun for a few hours or so to dry. Then I empty it and reattach it to the unit so it's ready for the next use.