How to Winterize Your AC System

A frozen AC system.
What You'll Need
Work gloves
Water hose
Foam or rubber pipe insulation
Duct tape
A waterproof air conditioning cover

With the cold months of winter fast approaching, fall is the perfect time to winterize your air conditioning system. Your home's air conditioning system works hard during the summer cooling the air inside your home. As winter approaches, the system will lie dormant for many months until it is called upon again when the thermometer starts to rise in the spring. To ensure your air conditioning system is up to the challenge after the thaw, it is important that you protect your system from the snow and ice of winter.

While this is a very simple DIY project, it is important that you complete this procedure on a warm and sunny day. This allows ample time for the system to dry completely.

Step 1 - Cut Power

Cut the power to the outdoor condensing/compressor unit. Most often, a quick disconnect circuit box is located within 3 feet of the outdoor unit. Open the box and either flip the circuit breaker or pull the disconnect plug to cut the power. In some applications, you can also cut the power to the indoor evaporator/air handler, but that will depend on if your furnace uses its blower to distribute heated air through your home. In that scenario, you would not want to turn off the blower unit.

Step 2 - Remove Weeds

A shovel near an AC system.

Don your work gloves and remove any foliage, weeds, or other debris from around your outdoor condensing unit. Use a water hose to thoroughly rinse both the outside and inside of the condensing unit to remove dirt, bird droppings, dust, and leaves.

Step 3 - Insulate Pipes

Insulate any exposed pipes. Make sure to insulate both the copper refrigerant lines as well as the PVC condensate or drain line. Rubber or foam pipe insulation is easy to install and available at most home improvement centers. Simply cut the insulation to the correct length and wrap it around the applicable pipe. Wrap a piece of duct tape around the pipe insulation where needed to hold it in place.

Step 4 - Use AC Cover

Once the unit is completely dry, cover it with a waterproof air conditioning cover. You can purchase one at most home improvement centers. Since they offer various sizes, measuring your unit before you go will help you purchase one that fits properly. You can use bungee cords or vinyl zip ties when necessary to help secure the cover to the outdoor unit and prevent it from detaching during windy conditions.

Step 5 - Check During the Winter

A man shoveling near an AC system.

During the winter months, check your outdoor unit periodically or after a storm and remove any ice, snow, or other debris from atop and around your outdoor unit. When weather permits, you should also remove the cover and check for any wildlife nesting inside your unit. The covered unit is an attractive and warm place for animals looking for an escape from the cold. If any are present, remove them in the appropriate manner and recover the unit.

When the warm weather returns and it's time to start up your unit, it is a good idea to hire an air conditioning contractor for a seasonal tune-up. Preventative maintenance helps to extend the life of your HVAC system as well as cut down on unexpected breakdowns and repair costs.