In most cases, yes—it is wise to turn off your air conditioning during the winter, but there are important exceptions and best-practice nuances.
When Turning Off the A/C Is the Right Move
Standard Central A/C (Cooling-Only System)
If your system is a conventional split A/C used only for cooling:
- Turning it off at the thermostat during cold months is recommended
- Prevents accidental operation during cold snaps
- Avoids unnecessary wear on the compressor
- Eliminates standby electrical draw (small, but real)
This is standard practice in colder seasons.
When You Should Not Turn It Off
Heat Pump Systems
If you have a heat pump, the outdoor unit is used for both heating and cooling.
- Do not turn off the system at the disconnect or breaker
- Use the thermostat’s HEAT or AUTO mode instead
- Shutting off power can disable defrost cycles and auxiliary heat controls
Many homeowners mistakenly “turn off the A/C” and inadvertently disable their heat source.
About Running A/C in Cold Weather
- Most residential A/C systems are not designed to operate below ~55°F outdoor temperature
- Operating A/C in cold conditions can damage the compressor without a low-ambient kit
- Thermostats normally prevent this, but manual overrides or miswiring can defeat safeguards
Should You Cover the Outdoor Unit?
This is optional and often misunderstood.
If you choose to cover it:
- Cover only the top, not the sides
- Use a breathable cover or plywood weighted down
- Purpose: keep leaves and debris out, not “insulation”
Do not fully wrap the unit, as this traps moisture and accelerates corrosion.
Best Practice Summary
| System Type | Recommended Action |
|---|---|
| Cooling-only central A/C | Turn off at thermostat |
| Heat pump | Leave powered; switch to HEAT |
| Window / portable units | Remove or fully winterize |
| Mini-split heat pump | Leave powered; use HEAT mode |
Bottom Line
- Yes, turn off a cooling-only A/C during winter
- No, do not shut off a heat pump at the breaker
- Use thermostat settings, not power disconnects
- Covering the unit is optional and should be done correctly