Once those first cool North Shore evenings arrive, most of us stop thinking about the air conditioner until the next heat wave. But how you put the AC to bed in the fall affects how reliably it wakes up in the spring — and whether next summer starts with a service call.
Central AC: end-of-season steps
- Turn it off at the source so it cannot accidentally run on a warm winter day (which can damage the compressor in cold weather).
- Clear debris away from the outdoor condenser unit — leaves, grass clippings, and sticks.
- Rinse the unit gently with a hose to clear off summer grime.
- Change the filter so the system is ready for clean airflow next season (and for the furnace now, if they share ductwork).
Should you cover the outdoor unit?
This is the question we get every fall, and the honest answer is: mostly no. Central AC condensers are built to sit outside year-round. A full wrap can trap moisture and invite rodents to nest inside. If anything, a simple cover over just the top to keep falling debris out is plenty — leave the sides open to breathe.
Mini-splits are different
If you have a ductless mini-split heat pump, you likely use it for heat in winter too — so do not shut it down. Instead, clean the filters and keep the outdoor unit clear of snow drifts through the season so it can keep pulling heat from the outside air.
Worth a fall service?
If your AC struggled this summer — weak cooling, odd noises, ice on the lines, or high bills — do not wait until spring. Having it looked at in the fall means the fix is done and the system is ready before the next hot stretch, instead of joining the June repair rush.
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Get a free hvac quote →Frequently asked questions
Should I cover my central air conditioner in winter?
Usually not fully — condensers are made to be outdoors, and a full cover can trap moisture and attract rodents. A cover over just the top to block debris is fine; leave the sides open.
Can running my AC in cold weather damage it?
Yes. Running central AC when it is cold out (below roughly 60°F) can harm the compressor. Shut it off at the disconnect or breaker in the fall so it cannot cycle on during a warm winter day.
Do I need to winterize a ductless mini-split?
If you use it for heat, no — keep using it, clean the filters, and keep the outdoor unit clear of snow. If it is cooling-only, treat it like central AC and shut it down for the season.