Self-clean mode dries the indoor coil after cooling, and on some units freezes and thaws it first to rinse off dust, so mold and odors have less to grow on. Run times range from 10 minutes (LG) to 90 minutes (Fujitsu COIL DRY) and up to 2.5 hours (Panasonic). It does not clean the filter, and Fujitsu says it cannot remove mold that is already there.
Self-clean mode is a cycle that dries, and on some units rinses, the indoor coil so mold and odors have less to grow on. On some units it runs the fan after cooling to blow the coil dry; on others it freezes the coil, thaws it to wash off dust, then dries it. It does not clean the filter, and it will not remove mold that is already there.
What self-clean actually does
When your AC cools, moisture from the room condenses on the cold indoor coil, and the coil stays wet after the unit stops. LG explains on its US support page for the Co code, and on an Auto Clean help page, that its drying cycle runs the unit "in fan mode for a certain duration to remove moisture from the evaporator," because moisture gives mold and bacteria a place to grow.
The manuals we opened describe three different designs under the "clean" label:
- Fan drying: the indoor fan keeps running after cooling stops to dry the coil (LG, Fujitsu).
- Freeze, thaw and dry: the unit frosts the coil, melts the frost to rinse it, then blows it dry (Midea and MrCool Active Clean, Gree Auto Clean, Haier Self-Clean).
- Drying plus an ion generator: Panasonic runs the fan at low speed with its nanoe X generator on.
How each brand describes it
Midea's US split owner's manual says Active Clean washes away dust, mold and grease on the heat exchanger "by automatically freezing and then rapidly thawing the frost," then keeps the blower running with hot air "to blow-dry the evaporator." The same wording appears in the MRCOOL mini-split remote manual. Gree's LIVO Gen4 owner's manual says that in Auto Clean the unit "will cool down and heat up rapidly," and that cool or warm air may blow during the cycle.
Haier's self-cleaning support page (Haier South Africa) describes condensing moisture on the coil, then drying it. It cleans the indoor coil first and the outdoor coil after. Haier units also run a short automatic indoor clean once cooling time adds up to about 300 hours.
Panasonic's CS-XZ operating instructions say Inside Cleaning may start on its own once a day after you switch the unit off, depending on how long it has run.
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How long self-clean runs, by brand
Run times differ a lot. These are the figures each maker states:
| Brand | Name on the remote or display | How it works | How long |
|---|---|---|---|
| LG | Auto Clean (auto drying on the US page), shows Co or SC | Fan only, after the unit stops | Unit turns off after 10 minutes (LED lamp models) |
| Fujitsu (ASU9RL, ASU12RL) | COIL DRY | Dries the indoor unit | 90 minutes, then stops on its own |
| Midea and MrCool | Active Clean, shows CL | Freeze, thaw, then hot-air dry | 20 to 45 minutes |
| Haier | Self-Clean | Condense, then dry; indoor coil, then outdoor | 20 to 30 minutes; automatic indoor clean about 9 minutes |
| Pioneer (Diamante, Quantum lines) | CLEAN | Cleans the indoor evaporator | About 30 minutes |
| Panasonic (CS-XZ) | Inside Cleaning | Low fan with nanoe X on | Up to 2.5 hours |
Fujitsu's figures come from its ASU9RL and ASU12RL manual and Pioneer's from its self-clean help article. If your model is not listed, the manual for your exact model number has the right figure.
What self-clean does not do
It does not clean the filter. The filter still needs washing by hand. Daikin's FTX30/36NVJU manual says clogged filters "cause inefficient operation and waste energy" and recommends cleaning them about every two weeks.
It does not kill mold that is already growing. Fujitsu is the bluntest: COIL DRY "cannot get rid of the existed mold or bacterium, and it has no sterilization effect either." Pioneer says its cycle removes "some" of the dust, dirt and microbes and does not replace regular maintenance. Panasonic still says the coils and fans should be cleaned periodically by an authorized dealer.
It does not fix the drain. The EPA's guide to mold and moisture says to keep air conditioning drip pans clean and drain lines "unobstructed and flowing properly." It also says not to run an HVAC system you know or suspect is contaminated with mold.
If you can see mold or the smell keeps coming back, read our guide on getting rid of mold in an AC or our list of reasons an AC smells. Water dripping from the indoor unit is a separate problem, covered in AC leaking water inside.
Other names for self-clean
The same idea goes by many names, and some brands use two functions for two jobs. Gree's LIVO Gen4 has both X-FAN, which keeps the indoor fan running a few minutes after shut-off to dry the coil, and Auto Clean, the freeze and heat cycle. Midea lists Anti-mildew and Active Clean as separate features. We cover the drying-only version in our anti-mildew mode guide.
The names we confirmed in manuals: Auto Clean (LG, Gree), COIL DRY (Fujitsu), Active Clean (Midea, MrCool), Self-Clean (Haier), CLEAN (Pioneer) and Inside Cleaning (Panasonic).
How to run self-clean
- Fujitsu: press COIL DRY during operation or after the unit stops. Press START/STOP to cancel.
- Midea and MrCool: press Clean on the remote; the display shows CL and the unit turns off when done.
- Gree LIVO Gen4: with the unit off, hold MODE and FAN together for 5 seconds.
- Pioneer: press CLEAN until the unit beeps; press power to stop.
- Panasonic CS-XZ: turn the unit off and hold the button shown in the manual for more than 3 seconds.
Some cycles have limits. Pioneer says to run it only with the room below 86°F and the outdoor temperature between 41°F and 68°F. Gree says Auto Clean will not work in very hot or cold outdoor weather. Both say odd noises during the cycle are normal.
How often depends on the brand. Gree suggests running Auto Clean once a month in a dusty room and once every three months otherwise. Pioneer also suggests about every three months. Haier and Panasonic units can start their cycles on their own, so you may not need to press anything.
Our guide to every AC mode covers the rest of the remote, including dry mode.
Frequently asked questions
How long does AC self-clean take?
It depends on the brand. LG's drying cycle turns the unit off after 10 minutes on LED lamp models. Midea and MrCool Active Clean takes 20 to 45 minutes, Haier 20 to 30 minutes, Pioneer about 30 minutes, Fujitsu COIL DRY 90 minutes, and Panasonic Inside Cleaning up to 2.5 hours. Your model's manual has the exact figure.
Does self-clean mode remove mold?
No. It helps keep the coil dry so mold has less moisture to grow on, but Fujitsu states that its COIL DRY cycle cannot remove existing mold or bacteria and has no sterilization effect. Pioneer says its cycle removes only some of the dirt and microbes. Visible mold needs a proper cleaning, and the EPA says not to run an HVAC system you suspect is contaminated.
Why is my AC still running after I turned it off?
A drying or cleaning cycle may be running. LG says that with auto drying on, the indoor unit can keep running for a while after you switch it off and shows Co or SC. Midea, Senville and MrCool units with anti-mildew keep running at very low power after cooling to dry the coil. Gree's X-FAN keeps the fan going for a few minutes.
Do I still need to clean the filter?
Yes. No self-clean cycle in the manuals we checked touches the filter. Daikin recommends cleaning filters about every two weeks, because clogged filters cause inefficient operation and waste energy. Panasonic also says the coils and fans should be cleaned periodically by an authorized dealer, even on units that run Inside Cleaning on their own.
Founder of Home Caprice. Ben started the site to simplify HVAC after dealing with the heating and cooling in his first apartment.