An air conditioner flashing light is the unit’s way of telling you something needs attention. A small light starts blinking on the indoor unit and the room stops getting cool. Most people assume the worst straight away. In a good number of cases the unit is doing exactly what the manufacturer designed it to do, and the blinking stops on its own within a few minutes.
The difficulty is that a flashing light means something different on every brand, and the brands do not agree on which lamp carries the message. This page sets out what each manufacturer actually publishes about its indicator lights, which flashing patterns are normal, which ones mean the unit has stopped, and what to do next.
Is the light flashing or is it simply lit
This is the first thing to settle, because on most brands a steady light and a flashing light mean opposite things.
A steady light usually means the unit is running, or that a timer has been set. Mitsubishi Heavy Industries Australia states that the yellow timer light on the indoor unit will remain on when the timer has been successfully set. Panasonic says that when a timer has been set, the timer setting repeats daily, and the lamp stays on to show it.
A flashing light is a message. It might be a normal one, such as defrost, or it might be the unit telling you it has stopped and needs attention. The rest of this page separates the two.
What the lights on each brand are called
| Brand | Indoor unit lights | What the manufacturer publishes |
|---|---|---|
| Daikin | OPERATION lamp, green. TIMER lamp, orange. Some models use a single Daikin eye that changes colour. | A blinking operation lamp is treated as a likely fault. The timer lamp flashing is a cleaning reminder on models with a Streamer unit. |
| Mitsubishi Electric | A single operation indicator lamp. | Lit means the unit is working toward the set temperature. Blinking means the room is approaching the set temperature, roughly 1 to 2 degrees away. |
| Fujitsu | OPERATION green, TIMER orange, ECONOMY green. | The operation lamp flashes slowly during automatic defrosting. A flashing timer lamp during timer operation indicates a fault with the timer setting. |
| Panasonic | POWER green, TIMER orange, plus feature lamps on some models. | The power indicator blinks at start up, before a timer start, and during defrost. A blinking timer indicator means the unit has stopped with a stored error code. |
| Mitsubishi Heavy Industries | RUN light, green or blue. TIMER light, yellow. | The run light blinks during hot keep, self clean and defrost. A self diagnosis table in the owner manual maps flash counts to faults. |
| LG | Two LED indicators at the lower corner of the indoor unit. | LG publishes the decoding method. The first LED gives the ones digit and the second gives the tens digit, so five blinks on the first LED is CH05. |
| Samsung | A display panel rather than plain lamps. | Samsung shows a letter and number code on the display. Write it down and call Samsung. |
| Kelvinator | Indicator light or display, model dependent. | Kelvinator publishes no decoding table. It asks owners to phone customer care and report the fault. |
| ActronAir | Operation lamp that flashes a count. | ActronAir does publish flash counts against codes, but in a service document rather than a consumer guide. |
| Braemar and Bonaire | Red LED that flashes a count on some products. | Seeley International publishes red flash counts, but the documentation is written for technicians and requires service screens and test equipment. |
Colours vary by model even within one brand. Older Fujitsu units in other markets used a red operation lamp and a green timer lamp, the reverse of the current Australian range. Check the lamp names printed on your own indoor unit before matching them to any list.
Flashing lights that are completely normal
Before assuming a fault, rule out the four behaviours that every brand builds in deliberately.
Defrost in heating mode
In cold weather the outdoor coil ices up and the system reverses briefly to clear it. The indoor fan stops and a light flashes while this happens. Fujitsu says the operation lamp flashes slowly during automatic defrosting. Mitsubishi Heavy Industries publishes the actual rate, a slow blink of 1.5 seconds on and 0.5 seconds off. Panasonic says the power indicator blinks during heat mode with no warm air supply because the unit is in defrost mode. Daikin says heating stops unexpectedly with the sound of water flowing and asks you to wait about 3 to 10 minutes.
If the flashing started on a cold morning, the unit was in heating, and warm air returns after ten minutes or so, that was defrost and nothing is wrong.
Warm up before heating
Mitsubishi Heavy Industries calls this hot keep. Airflow stops for 2 to 5 minutes to prevent blowing cold air until the indoor heat exchanger has warmed up, and the run light blinks while it waits. Panasonic says the power indicator blinks at the initial stage in heat mode. Daikin notes that warm air does not flow immediately after starting heating.
A timer is set or about to start
Panasonic publishes that the power indicator blinks before the unit is switched on when an on timer is set. Daikin says that on models with the Daikin eye, the indicator changes to orange for about 10 seconds and then returns to the colour of the operation mode for 3 minutes.
Fujitsu General Australia points out a specific trap here. An active weekly timer can stop the unit responding to a normal manual on command, and the lights flash a few times in response. The fix is to look for the word WEEKLY on the remote display and press the weekly button to turn it off.
Filter and self clean reminders
Fujitsu uses the economy lamp for this and says it flashes when it is time to clean the air filters. Daikin uses the orange timer lamp to signal that the Streamer unit needs cleaning, with a reset button to clear it. Samsung shows CF for a filter reminder and Cl for auto clean on the display panel. Mitsubishi Heavy Industries lists clean operation as one of the reasons the run light blinks.
None of these is a fault. If your unit is due for a filter clean, our guide on how often to replace air conditioner filters covers what to do.
When a flashing light means the unit has stopped
The pattern is easy to recognise. The unit stops producing air, the flashing continues rather than clearing after a few minutes, and pressing the remote does nothing useful. At that point the manufacturers are consistent about what they want you to do.
Daikin tells owners to turn off the power with the circuit breaker and restart operation with the remote controller, and says that if the operation lamp is still blinking, check the error code and consult your dealer. Daikin also asks you to check the air filters and make sure the inlets and outlets of both units are not blocked before doing anything else.
Panasonic says that if the unit stops and the timer indicator blinks, use the remote control to retrieve the error code, then turn the unit off and give the code to an authorised dealer.
Fujitsu General Australia says flashing lights mean the unit may have detected a fault that requires maintenance attention, and that a flashing green or orange light can signal issues like blocked filters, low refrigerant or fan malfunctions.
Kelvinator asks owners to contact its customer care centre to report the fault and organise a service call. ActronAir tells owners to turn off the unit immediately and contact ActronAir service.
Why most brands will not tell you what the blink count means
Search for a blink count and you will find pages of tables. Very few of them come from the manufacturer.
Daikin does not publish a blink count table at all. The code is read on the remote screen, not counted from the lamp. Mitsubishi Electric publishes no blink count table either, and its manual says only to stop using the air conditioner and consult your dealer. Panasonic routes the owner to the code, then to the dealer. Samsung shows a code on the display rather than a count. Kelvinator directs owners to the phone.
Fujitsu General Australia is explicit about the reason. Its own error code reference states that it supports field technicians, and warns that the same LED count or code can represent a different fault on another model. That is the whole problem with a generic online blink count table. A count that means a fan motor fault on one chassis can mean a sensor fault on the next one.
Two brands do publish counts to owners. Mitsubishi Heavy Industries includes a self diagnosis table in the end user manual, and LG publishes the decoding method on its consumer help pages.
If your brand does not publish a table, the useful thing you can do is count. Note how many times each lamp flashes, whether the lamps flash together or alternately, and how long the pause is before the pattern repeats. Fujitsu General Australia specifically asks owners to record the exact light pattern before contacting support. That count is what shortens the service call.
The power cycle wait time is different for every brand
Almost every brand publishes a power cycle as the first thing to try. What none of them agree on is how long to leave it off.
| Brand | Published wait |
|---|---|
| Daikin, regional guidance | Breaker off, wait about 1 minute, then on |
| Daikin, global guidance | Circuit breaker off for 20 minutes, then restart |
| Mitsubishi Heavy Industries | Turn off the power supply immediately and turn it on after 3 minutes |
| LG | Reset the breaker approximately 5 minutes later |
| Fujitsu General Australia | Isolation switch off for at least five minutes |
| Panasonic | Reset the isolator switch by the outdoor unit and wait 5 minutes before turning it on again |
Use the figure your own brand publishes. If you cannot find one, five minutes sits in the middle of the published range and is long enough for the control board to drop power completely.
One thing to expect afterwards. Daikin says the air conditioner automatically resumes operation in about 3 minutes, and that operation does not start soon after a restart because this is to protect the air conditioner. A few minutes of nothing happening after a power cycle is normal, not a second fault.
When to stop and turn the power off
There is a short list of conditions where the answer is not a power cycle.
- A burning smell. Mitsubishi Electric says that on an abnormal condition such as a burning smell you must stop the air conditioner and disconnect the power plug or turn the breaker off.
- Water leaking or dripping from the indoor unit.
- The breaker tripping repeatedly.
- An abnormal sound that was not there before.
- A power cord that becomes unnaturally warm.
Every brand on this page lists conditions of this kind as reasons to stop using the unit and call for service rather than reset it. If you are dealing with water rather than lights, our guide to an air conditioner leaking water covers the causes.
How to read the code on the brands that allow it
Three brands let an owner retrieve the code without a technician.
Daikin publishes a remote controller method. Hold the cancel button for about 5 seconds, a code blinks in the temperature display, then press cancel repeatedly until you hear a long beep. That is the stored code.
Panasonic publishes a check button method. Press and hold the check button for 5 seconds with a pointed object, then press the timer up or down button repeatedly to cycle through codes until the unit beeps. Panasonic states that repairs and complex troubleshooting should be performed by a qualified service technician, and that the code exists so you can hand it to one.
Fujitsu publishes a service check mode on the remote for current Australian wall mounted models, which shows a two digit code on the remote display.
Our guide to air conditioner error codes covers what to do once you have the code, and the brand pages such as Daikin error codes go into the specific families.
Common questions about flashing air conditioner lights
Can I keep using the air conditioner while a light is flashing?
If the unit is still producing air and the flashing matches a normal behaviour such as defrost or a timer, yes. If the unit has stopped, no. The lamp is reporting a protection trip and the system has taken itself out of service to avoid damage.
Does a flashing light always mean an expensive repair?
No. A large share of stopped units come back after a filter clean, a clearance around the outdoor unit and a power cycle, because the fault was a temperature or pressure protection caused by restricted airflow. That is why every manufacturer puts the filter check first.
Why does the light flash again a day later?
A fault that clears on a power cycle and returns is telling you the underlying cause is still there. Panasonic names a short list of alarm codes that may clear on a restart and says that a recurrence requires the dealer. A repeat within a day or two is worth a service visit rather than a third reset.
My unit has no lights at all, just a screen
Ducted systems and units with a wired wall controller usually show a code on the controller instead. Panasonic ducted controllers show an alarm icon with the defective indoor unit number and the code. Fujitsu notes that on ducted units with a wired controller the timer indicator lamp on the indoor unit does not light at all, because that lamp is used for wireless remotes only.
The lights flash a few times and then everything goes dead
Fujitsu General Australia attributes this specific pattern to an active weekly timer, which can prevent the unit from responding to a normal manual on command. Check the remote display for the word WEEKLY and turn it off.
What to do next
Work through it in this order. Decide whether the light is flashing or steady. Rule out defrost, warm up, a timer and a filter reminder. If the unit has stopped, check the filters and the clearance around both units, then power cycle using the wait time your brand publishes. If the lamp is still flashing afterwards, count the pattern, retrieve the code if your brand allows it, and book a technician with that information in hand.
A flashing lamp is the obvious one, but there are quieter signs an air conditioner needs repair worth knowing before the season starts.
That last step is what turns a long diagnostic visit into a short one. If you are in Melbourne and the light is still flashing after a reset, you can request a quote or call and describe the pattern over the phone.
For general advice on staying safe around electrical appliances at home, see Energy Safe Victoria.
Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles