Winterizing a Condensing Unit


When the temperature starts to drop, we forget about the condensing units to our central air conditioning systems. We concentrate on our heating systems and do not remember that there is some maintenance involved with these outside units.

Here are the necessary steps, all very simple, but needed to protect our expensive air conditioning systems.

Step 1:

Go to the electric panel in the building and after determining which breaker will shut power off to the condensing unit, turn that breaker off. This will keep the unit from accidentally being turned on during the cold winter months, which could seriously damage the equipment.

Step 2:

Remove all debris from around the condensing unit. Piles of leaves seem to always collect around and behind the condensing units, these should be cleaned away. Any vines that have grown around and up to the units must be removed; they can damage the fins on the copper coils. All sticks and basically all trash and yard waste should be cleaned up. If this material is allowed to stay near the unit over the winter it will allow moisture to build which aids in the corrosion of the unit’s parts.

Step 3:

Anything that is stored behind and next to the condensing unit must be removed. Many people have a disposition to placing and hiding ladders, building material and the like in the same areas as the units. This is not a good idea in any weather, but during winter there is a great chance, as no one is watching them, that something could knock this material into the unit. The copper on the units is very thin and easily damaged, so you should not wait for an accident to happen. Once the copper is punctured it usually cannot be repaired.

Step 4:

Visually inspect the condensing unit. Taking several minutes to inspect the unit can go a long way in maintaining the system. Now that all the debris is cleared away, bend or kneel down and look at the lineset, which is the copper pipes leave the unit and enter the building. See if there is any damage to the insulation, if the lines have any visible kinks, also look to see if the area where the lineset enters the building is sealed. You will want to repair the insulation before the cooling season, but the holes should be sealed to prevent drafts.

Also the electric should be inspected. Take a look at the 220v electric line; there should not be any bare or loose wiring. If there is damage repair it now or note for the springtime. The 24v wiring from the furnace or air handler should be checked. Many times, this is damaged from lawn mowers and weed trimmers.

Step 5:

Cover the unit. Only the top of the condensing unit should be covered. Home centers sell covers that cover the entire unit, top and sides, but this is not what you want. When the top and sides are covered moisture is allowed to stay inside the casing of the condensing unit; with no air flow it will never dry out. This constant state of being wet will corrode the components of the units very quickly.

The top can be covered with a precisely cut piece of plastic, a tarp held down with bungee cords, or a large trash bag that is weighted down. The cover can be as simple as the one shown in the picture, a piece of plastic with a small sheet of plywood to hold it down. It’s not very fancy but functions well.

During these months you will want to keep all debris from getting inside the unit cover. As most condensing units are placed near buildings there is a good chance that ice or large chunks of snow could fall from a roof and damage the copper coils. As I stated before, when this happens the copper is usually not repairable. It is also best not to let the late falling leaves accumulate in the unit; this will only start to clog up the coils which will lower efficiency in the long run.

These simple steps will allow the condensing unit to weather the winter with no damage. In as little as 30 minutes the unit can be cleaned, checked and covered; thus giving us the satisfaction of knowing the condensing unit is properly winterized.

Condensing is an important point to take care of depending on the weather conditions and if you have a good air conditioner, then half the problem is solved where you look up better options like blaux portable ac online to make things better during peak winter.


I am happily married with two great children. I have owned my own plumbing, heating and HVAC company for over 17 years, opening when I was 24. Operating a business hands on for so many years has given me a unique perspective to the trades. My niche is being able to relate customers of all levels, guiding them along the way.