Do I need to "winterize" my AC unit?

I've read that I need to empty the pipes or hoses coming from the unit and use a wet vac to suck up water in the drain pan. Is this correct and really necessary? I live in Western PA.
  7 answers
  • Leslie D Leslie D on Sep 20, 2012
    Do you have an AC Unit or an evaporative cooler (swamp cooler)? You most definately need to winterize a swamp cooler, as water in supply lines and water pan can freeze, then thaw, causing leaks and damage.... but anything other than removing debris around a typical AC unit, and possibly covering it for the season is unnecessary.
  • Donna R Donna R on Sep 20, 2012
    Thanks for the reply. I have a regular AC unit and bought a cover for it for the winter, so I guess as soon as I clear away some leaves I'm all set!
  • Warren G. Warren G. on Sep 21, 2012
    On a two part AC only. If you have a drain line that goes from the inside to the out side unit and then it drains to the ground, I would pour some winter treatment fluid in the drain pan inside until it over flows to the ground out side. This winter treatment fluid I am talking about can be found in the trailer supply section of the big box store. It is made for winterizing your water tanks in trailer. You drain pipe is out side and filled with water as it has a "P" trap just like your sink does. if you don't winterize it you will have a busted pipe from freezing. If you get the type of winterizing fluid made for water tanks it will not harm the ground, so you can just fill the pipe up and in the spring when you start you system up again the drain over flow will just flush it out on the ground . No harm no fowl....
  • Donna, Warren is correct on this. If your AC system is located in the attic, you need to winterize the trap that is the little plastic U shaped thing that is right next to or very near to the blower in the attic. Using anti-freeze as suggested will work, or you can simply, by using a shop vacuum simply suck the water out of the pipe. The next thing to do is to change your filter. Then on the outside, using a garden hose, wash off the unit and clean it. Once done remove, or turn off the power to the unit from the outside disconnect to assure the system will not run by accident during the colder months. Place the disconnect on top of the AC unit and cover it with plastic and some bungee cords to keep the leaves out. You do not have to cover the sides, unless the unit would be exposed to salt sprays in some fashion. It is better that air flows through the unit to keep it dry. But the cover on the top will prevent leaves and debris from getting inside and plugging the drain holes on the bottom of the unit. By placing the shut off switch under the cover this will assure that you remove the cover before you turn the unit back on. Be sure to turn on the power to the unit and wait for at least 24 hours before starting the AC again in the spring.
  • Donna R Donna R on Sep 21, 2012
    Good things to know -- thank you. I just assumed that the whole unit should be covered since the covers they sell do exactly that.
  • Warren G. Warren G. on Sep 21, 2012
    The reason I prefer to use the winterizing fluid is that sometime your drain pipe does not run straight and has a dip in the line and water can settle in the low spot. When using the vacuum air will flow over top of the low spot and not suck out the water. This leaves water in the line and may still cause you problems. But the winterizing fluid is blue in color and you know when the pipe is full and it displaces the water protected your pipe 100%. Just a different point of view...But you still have to disconnect the electricity, clean and cover the outside unit as suggested by Woodbride Enviromental...
  • The full covers are ok, I just like doing the top only. My main reason is that it makes a nice cozy home for mice if they are protected from any winds. And with a complete cover over the unit, this makes a tent for them to overwinter in the unit. I fact I use a large garbage can lid that I found. It fits nicely over the top of the round grill and I run the bungee cords though the handles to hold it in place.
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