Should I Turn AC Off in Winter? What Homeowners Need to Know
As temperatures drop, homeowners start prepping their HVAC systems for the cold months ahead. One of the most common questions we hear is: “Should I turn AC off in winter?”
The short answer: Yes – if you have a traditional air conditioner. Turning off your outdoor AC unit for the winter helps protect it from accidental operation, unnecessary wear, and winter weather damage.
Here’s everything you need to know about shutting down your AC for the season, plus important exceptions if you own a heat pump.
Why You Should Turn Off Your AC in Winter
When homeowners ask, “should I turn the air conditioner off in winter?” what they’re really asking is whether the outdoor condenser needs to be powered down. For a standard central air conditioner, turning off the AC at the breaker is a simple and important winterization step.
1. Prevent Accidental Activation
Even on a mild winter day, your thermostat may try to call for cooling. If the AC kicks on while the top of the unit is covered in ice or snow, the fan can jam or the system can freeze.
Turning off the breaker ensures the AC can’t turn on accidentally.
2. Protect Internal Components
Running an AC in freezing temperatures can cause the oil inside the compressor to thicken, making it harder for components to move and potentially causing long-term damage.
3. Avoid Unnecessary Wear
Your AC isn’t built to operate in cold weather. Shutting off the power keeps the system dormant and safe until spring.
How to Turn Off Your AC for Winter
Turning off the AC is fast and easy:
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Locate the AC disconnect box—usually a small grey box mounted to the wall by your outdoor unit.
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Flip the breaker switch to OFF.
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Close the cover securely.
This ensures the system stays off all winter, even if someone accidentally bumps the thermostat.
Why Turning the Thermostat to “Heat” Isn’t Enough
Many homeowners assume that switching the thermostat from cool to heat is all they need to do to shut down their air conditioner for the winter. Unfortunately, that’s not enough to fully protect the outdoor unit.
Here’s why:
1. The Thermostat Can Still Call for Cooling
Even in winter, your home may have a warm, sunny day or indoor heat buildup that triggers a cooling call. If the thermostat senses the home rising above the cooling setpoint—even briefly—it can try to activate the AC.
2. The Outdoor Unit Isn’t Designed to Operate in Freezing Temps
If the AC were to turn on in cold weather, the outdoor fan could be frozen, the coils could be covered in ice, and the compressor oil could be too thick to circulate properly. This can lead to serious damage.
3. Power Must Be Cut at the Outdoor Disconnect
Your thermostat only controls communication—not power.
To guarantee the AC won’t run at all, you need to:
- Locate the outdoor disconnect box
- Flip the AC breaker to OFF
This step physically cuts power to the condenser so no signal from the thermostat can accidentally start the system.
4. Maintenance or System Glitches Can Also Trigger Cooling
Thermostats sometimes get reset during power outages or software updates. If settings revert, your system may default to cooling mode. Turning off the breaker prevents any chance of the AC kicking on unexpectedly.
Winterization Tips for Your AC Unit
Shutting off the power is just the first step. To keep your air conditioner in good shape all winter, consider these additional tips:
✔ Clear Debris Around the Unit
Remove leaves, sticks, and dirt from around the base of the condenser. This helps prevent moisture buildup and corrosion.
✔ Give the AC a Light Rinse
Spraying the unit with a garden hose (before freezing temps arrive) removes dust and grime that can trap moisture.
✔ Check Insulation on the Refrigerant Line
Replace any damaged insulation to help protect the line from cracking in cold weather.
✔ Keep Your HVAC Filter Fresh
Even though the AC is off, your furnace will still rely on your home’s air filter for proper airflow.
✔ Consider Covering the Unit (But Only If Done Correctly)
Some homeowners choose to cover their AC for winter, but it must be done properly to avoid trapping moisture or attracting rodents.
👉 We break down the pros and cons in our full post: “Should I Cover My Air Conditioner in the Winter?”
IMPORTANT: This Does Not Apply If You Have a Heat Pump
Heat pumps can be confusing because they look exactly like traditional AC units, but they work year-round, providing both cooling in summer and heating in winter.
So, if you’re asking:
“Should I turn AC off in winter if I have a heat pump?”
The answer is no.
Heat pumps must remain powered on because:
- They run all winter long to heat your home
- The outdoor unit is designed to withstand cold temperatures
- Shutting off the breaker would leave you without heat
- The system has built-in defrost cycles to manage ice buildup
If you’re unsure whether you have a heat pump or a traditional AC, we can help, just give us a call.
Keep Your AC Protected This Winter
Preparing your air conditioner for winter doesn’t take long but doing it correctly can make a big difference in the health and longevity of your system. From shutting off the AC breaker to clearing debris and checking insulation, these small steps help ensure your unit is protected while it’s not in use.
If you want the peace of mind that your AC is truly ready for the season, Quality Comfort Home Services can help. Our technicians provide thorough AC maintenance that includes cleaning, inspecting components, checking refrigerant levels, and making sure the system is properly winterized. We’ll get your unit prepped for the cold months and set up for a smooth start when spring returns.
Whether you need help identifying your system type, turning off the AC safely, or preparing your HVAC equipment for the weather ahead, we’re here to make it easy. Contact Quality Comfort today to schedule your seasonal AC maintenance and protect your home’s comfort all year long.
