How long does a window air conditioner last?
Updated August 2026
A window air conditioner lasts 8–10 years, shorter than a central system because it packs a compressor, coils, and fan into one small cabinet that runs hard through summer and often sits in the weather all winter. Two habits set where yours lands in that range: keeping the filter and coils clean so it can breathe, and pulling it or covering it for the off-season instead of letting rain and ice work on it. Neglect either and 8 years quietly becomes 5.
Lifespan by type and situation
| Type or situation | Typical lifespan | Why |
|---|---|---|
| Cleaned and stored each winter | 9–10 years | Clean coils and no weather exposure reach the top |
| Left in the window year-round | 6–8 years | Winter rain and ice corrode the coils and cabinet |
| Filter rarely cleaned | Cut 2–3 years | A choked filter ices the coil and overheats the compressor |
| Oversized for the room | Short-cycling | It cools fast, shuts off, and cycles the compressor to death |
| Runs 24/7 in a hot climate | 5–7 years | Constant compressor duty wears it faster than seasonal use |
Signs yours is near the end
- The room takes far longer to cool, or never reaches the set temperature
- Warm or weak airflow even after you have cleaned the filter
- Water dripping inside the room or pooling under the unit
- Loud rattling, grinding, or a buzzing compressor that struggles to start
- A musty smell, ice on the coils, or a sudden spike in the electric bill
How to add years
A window unit lives or dies on airflow and off-season care. Cleaning the filter every few weeks in season, and rinsing the coils once a year, keeps the compressor from running hot, which is the failure that scraps the whole unit. When cooling season ends, pull the unit and store it upright indoors, or fit a snug outdoor cover, so winter moisture is not corroding the coils and shorting the controls. Make sure it drains and tilts slightly toward the outside so condensate runs out instead of pooling inside. Match the unit's BTU rating to the room too, since an oversized model short-cycles and wears out early. The seasonal checklist covers it; for whole-home cooling, a central system lasts far longer.
What it costs to replace: plan on $150–500 depending on capacity. Replacing on your own schedule, before it fails, is almost always cheaper than the emergency version. The home maintenance cost calculator helps you set the money aside before it comes due.
OnOtto tracks your window AC age and service history, and warns you before end of life instead of after the flood.
Track your home's systems, free for 30 daysFrequently asked questions
Should I take my window AC out for the winter?
Ideally, yes. Removing the unit and storing it upright indoors protects the coils and controls from freeze-thaw, blocks the cold-air leak a window unit creates, and adds years to its life. If it is too heavy or awkward to remove, buy a fitted cover made for outdoor use and seal the interior gaps against drafts. Either way, an AC left uncovered in the window all winter corrodes faster and often fails a season or two early. Storage is the cheapest way to protect a $150–500 appliance.
Why is my window AC leaking water inside?
Usually it is not tilted correctly. A window unit should sit dead level side to side and lean very slightly toward the outdoors so condensate drains out the back, not onto your floor. Check that first. The other causes are a drain channel packed with dirt and algae, a frozen coil from a dirty filter that is now melting, or ice buildup from running the unit when it is too cool outside. Clean the filter, clear the drain, and correct the tilt before assuming the worst.
Is it worth repairing a window air conditioner?
Rarely, given the price. Because a new unit runs just $150–500, any repair involving the sealed refrigeration system, the compressor, or a control board costs more than replacement. What is worth doing yourself: cleaning the filter and coils, clearing the drain, straightening bent fins, and swapping a $10–20 knob or a fan-motor capacitor. If the compressor is dead, the unit ices up with clean airflow, or it is past 8 years and cooling weakly, replace it rather than pay a tech.