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When the summer heat gives way to cool air and autumn foliage, it’s time to learn how to winterize an AC unit. For homeowners in the St. Louis area, this involves following the manufacturer’s instructions and protecting the unit without trapping moisture inside. A few practical steps, plus professional maintenance as needed, can help you avoid costly breakdowns.
Identifying Your Outdoor Equipment
Before you schedule winterizing service, confirm whether your outdoor unit is part of an air conditioner or a heat pump. These HVAC components may look similar, but they have different winter maintenance requirements.
A central air conditioner typically cools a home during the warmer months and remains off during winter. Heat pumps have both heating and cooling functions, so the outdoor unit continues to function during the winter. If you have a heat pump, it needs a reliable power source and consistent airflow.
Check your owner’s manual or ask one of our technicians if you aren’t sure what you have. Don’t disconnect or fully cover an outdoor unit used for heating.
How to Winterize an AC Unit Step by Step
When you’re ready to winterize, choose a mild, dry day. Good weather makes it easier to inspect your equipment and notice signs of damage. Consult your owner’s manual for information on manufacturer-specific shutdown procedures.
Before you begin working, grab a pair of gloves and a yard waste bag. If you’re unsure of anything, call Anton’s for assistance.
1. Set the Thermostat for the Season
Once the cooling season ends, switch your thermostat to the heating setting. The right time to do this depends on your preferences. Fall temperatures in St. Louis can vary, so switch to heating when you need it rather than following a fixed date.
Don’t assume that you need to turn off your AC breaker. Some models have manufacturer-specific requirements, so check the owner’s manual or ask one of our technicians if a seasonal electrical shutdown is necessary.
2. Clear Leaves and Yard Debris
Remove loose leaves, sticks and grass clippings from around the outdoor unit. Keep nearby trees and plants trimmed to the manufacturer’s clearance requirements. For example, Trane recommends keeping plants 2 to 3 feet from the unit on all sides and 5 feet above it.
If you need to touch the unit, follow the instructions in the manual to disconnect the power. Simply turning off the thermostat doesn’t isolate power to your AC equipment. Leave any grille removal, internal cleaning or electrical work to a professional from Anton’s.
For more guidance, see our guide to cleaning an outdoor AC unit and condenser coils. Check your owner’s manual before using any water or cleaning products.
3. Check for Visible Damage
Next, walk around the AC cabinet and check for any damage that occurred during the summer. Look for:
- Damaged insulation around the refrigerant tubing
- Exposed or damaged wiring
- Loose panels
- Visible corrosion
- Crushed or bent fins
If you’re concerned about a particular component, take a photo to share with your Anton’s technician. Don’t adjust the refrigerant lines, open electrical components or attempt to repair damaged wiring. A professional inspection can help determine the best way to address the damage.
4. Look Above and Around the Unit
When learning how to winterize an AC unit, the ground isn’t your only concern. You also need to look above your equipment. Check for roof runoff, clogged gutters or untrimmed branches that could cause debris or water to enter the unit.
Keep the area around your equipment empty to encourage proper drainage. Don’t stack patio furniture, garden supplies or firewood against the outdoor cabinet.
Should I Cover My Air Conditioner in the Winter?
Outdoor AC equipment is designed for exposure to low temperatures and inclement weather. A full cover may not be necessary, but it depends on your location and AC model.
Manufacturer-approved toppers can help prevent problems caused by falling leaves and debris. If you use one, don’t wrap the cabinet tightly. This can trap moisture and restrict airflow. It is recommended to consult your owner’s manual for model-specific guidance.
Where a Fall HVAC Tune-Up Fits In
Winterizing your AC unit doesn’t eliminate the need for professional maintenance. A fall HVAC tune-up is the perfect time to address cooling issues while preparing your heating equipment for the winter ahead.
Depending on your needs, a tune-up may include:
- Inspecting and cleaning or replacing air filters
- Testing and calibrating the thermostat
- Tightening electrical connections
- Inspecting capacitors and contactors
- Checking the blower motor
- Verifying proper airflow
- Lubricating moving parts
If you’re thinking about hiring a winterizing service, find out exactly what’s included. Some companies provide basic winterization, while others perform additional HVAC tasks.
Monitor the Unit During the Winter
After storms, check for fallen branches and debris around the AC cabinet. Avoid shoveling snow onto the unit or spraying de-icing chemicals in the direction of your equipment.
If you have a heat pump, continue following the manufacturer’s recommendation for airflow clearance. It’s normal for light frost to accumulate on the outdoor unit, but heavy ice needs professional attention. Avoid removing ice from the coils or pouring hot water over the equipment to encourage thawing.
Give Your AC a Clean Start Next Spring
Knowing how to winterize an AC unit involves taking common-sense precautions. Keep the area clear, follow the manufacturer’s shutdown instructions and have any damage assessed by a professional.
Before it gets warm again, remove the seasonal cover (if applicable) and follow manufacturer guidance for starting up your AC system. Combine these habits with routine maintenance from the professionals at Anton’s.
