Hitachi air conditioner symbols are easy to read once you know the handful that matter. You are standing in front of the wall unit with the remote in your hand, and there is a symbol on the screen you have never seen before. Maybe the room will not cool. Maybe a small light is flashing and nothing responds. The manual is somewhere in a drawer, and when you find it the answer is buried on page forty.
This page is the shortcut. Every Hitachi air conditioner symbol below is set out in plain language, taken from Hitachi documentation for Australia rather than from guesswork. Start with the chart, then read the section that matches whatever is on your screen.
Hitachi air conditioner symbols at a glance
Here is the quick answer. Symbols vary between models, so if something on your remote is not listed, check the section further down on faults and on locked remotes. If your system is a different brand, our general guide to air conditioner symbols covers the ones every manufacturer shares.
| Symbol | What it means | What to do |
|---|---|---|
| Snowflake | Cool mode. The unit removes heat from the room. | Set a temperature below the current room temperature, or cooling will not start. |
| Sun | Heat mode. The unit brings heat in from outside. | Use it when it is cold outdoors. Hitachi advises against running heat mode when the outdoor temperature is above 21 degrees. |
| Water droplet | Dry mode. The unit works as a dehumidifier. | Use it on muggy days when the room does not need cooling. Fan speed drops automatically, so it runs quietly. |
| Windmill or fan | Fan mode. Air is circulated only. | Expect air movement, not cooling. The compressor does not run, so it uses very little power. |
| Auto | Auto mode. The unit chooses cooling or heating for you. | Leave it alone unless the choice it makes is wrong for the room, then set the mode by hand. |
| Bars or blocks | Fan speed. Low, medium, high or auto. | More bars means more airflow. Auto adjusts the speed as the room temperature changes. |
| Arrows or a moving blade | Swing. The louvre that aims the air. | Use it to direct air up, down, left or right, depending on the model. |
| Crescent moon | Sleep. Sometimes shown as GoodSleep. | The unit eases the temperature and drops fan speed for the night. |
| Leaf or Eco | Eco mode. Energy saving. | The set temperature shifts a little to save power while staying comfortable. |
| Powerful or a filled arrow | Powerful mode, sometimes called turbo. | Maximum output for a short burst, then the unit goes back to what it was doing. |
| Quiet or Silent | Silent mode. The indoor fan runs at its lowest speed. | Best once the room has already reached temperature. |
| Clock or timer | A timer is set. | The unit will switch on or off by itself. Clear the timer if you did not mean to set one. |
| Filter | Filter sign. Time to clean the main filter. | Clean the filter and reset the sign. This is maintenance, not a fault. |
| Snowflake with water, or Clean | FrostWash. A cleaning cycle for the indoor coil. | Let it finish. Keep windows and doors closed while it runs. |
| Padlock | Lock, also called prohibition. The controls are locked. | Nothing will change until you unlock it. See the unlocking section below. |
| House or Leave Home | Leave Home. Minimal heating while nobody is there. | It holds the room near 10 degrees. Switch it off when you are back. |
| Small signal mark | Transmission sign. The remote is sending a command. | Nothing to do. It confirms the remote is talking to the unit. |
| Cross or error mark | Invalid operation sign. The command did not go through. | Try again. If it keeps showing, work through the remote checks below. |
Every meaning above comes from Hitachi documentation published for Australia. Where a symbol differs by model, the page says so rather than guessing.
The five mode symbols and what each one actually does
Mode is the setting that matters most. Choose the wrong one and nothing else on the remote will make the room comfortable.
Snowflake, the cool mode symbol
The snowflake is cool mode, and it is the setting most people leave the unit on all summer. The air conditioner takes unwanted heat out of the room and moves it outside.
One detail catches people out. Cooling will not start if the temperature you have set is higher than the temperature in the room. If the room is 24 degrees and the remote says 26, the unit has nothing to do. Drop the setting below the room temperature and it will start.
Hitachi residential units can be set between 16 and 32 degrees. When you first switch on you will see a gap between the set temperature and the room temperature, which simply means the unit has not brought the room around yet.
Sun, the heat mode symbol
The sun is heat mode. The unit reverses, pulls heat out of the outdoor air and brings it inside, which is why a reverse cycle system can warm a Melbourne house in July without an element or a flame.
Hitachi gives clear limits. Heat mode is best used when the outdoor temperature is below 21 degrees, and running it when the outdoor air is warmer than that is not recommended, as it puts the unit under strain for no benefit. At the cold end, operation is recommended down to about minus 15 degrees outdoors, which no Melbourne winter will test.
Water droplet, the dry mode symbol
The droplet is dry mode, and it is the most useful symbol almost nobody presses. In dry mode the air conditioner works as a dehumidifier, pulling moisture out of the air rather than chasing a temperature.
On a sticky evening when the room is not really hot but feels heavy, dry mode is the right answer. Hitachi recommends a room temperature between 20 and 26 degrees for dehumidifying, and the setting range is the same 16 to 32 degrees as cooling.
Dry mode also drops the fan to a low speed on its own, so it is noticeably quieter than cooling. That makes it a good overnight setting in humid weather.
Auto mode
Auto lets the unit decide. It switches between cooling and heating based on the conditions in the room and tries to hold both temperature and humidity steady.
It works well in shoulder seasons when a room can need cooling in the afternoon and a little warmth at night. If the choice it makes is not the one you want, simply set the mode by hand instead.
Windmill, the fan mode symbol
The windmill or fan symbol is fan mode. The indoor fan runs and moves air around the room, and that is all it does.
The compressor stays off, which is why fan mode uses so little electricity. It is worth knowing what this means in practice. If the room is not getting cooler and the remote shows the fan symbol rather than the snowflake, the unit is not broken. It has simply been left on the wrong mode, and this is one of the common call outs that turns out not to be a fault at all.
Fan speed and airflow symbols
Fan speed is usually shown as a row of bars or blocks. More bars means more air. Most Hitachi remotes offer low, medium, high and auto, and on auto the unit raises and lowers the speed as the room temperature moves.
The swing symbol, often arrows or a small moving blade, controls the louvre that aims the air. Depending on the model the air can be swung up, down, left or right. During normal operation the horizontal deflector sets itself to a sensible angle, and you can override it with the up and down buttons if you would rather aim the air somewhere specific.
A practical tip for summer. Aim the air high rather than straight at the sofa. Cool air falls, so pointing it at the ceiling mixes the room more evenly and stops one person freezing while the far corner stays warm.
Comfort and energy saving symbols
Silent or quiet
Silent mode runs the indoor fan at its lowest speed for minimal noise. Because it reduces the volume of air the indoor unit treats, it is best used once the room has already reached the temperature you want, rather than at the start when you need the unit working hard.
You can press Silent during auto, heat, dry, cool or fan operation. To turn it off, press the on and off button, the Silent button again, or the fan speed button. Most controllers have a direct Silent button, and if yours does not, the same result comes from setting the fan to its lowest speed.
Eco and Smart Eco
Eco mode works in both cooling and heating. It nudges the set temperature up or down to a more efficient figure while keeping the room comfortable, which is a gentler way to cut running costs than simply turning the unit off.
Some Hitachi models add Smart Eco. That function watches whether the room is occupied, switches to Eco when everybody leaves, and returns to the previous setting when somebody comes back.
Powerful, sometimes called turbo
The Powerful symbol runs the compressor and fan motors at maximum capacity to reach the set temperature faster. Press it during auto, heat or cool operation and the unit gives maximum output for around 20 minutes, although the exact duration varies by model, then returns to the settings it had before.
Two limits are worth knowing. Powerful will not add anything if the unit is already running at maximum capacity, and it will not increase output in the moments before a defrost cycle during heating.
Sleep and SleepSense
The sleep symbol, usually a crescent moon and sometimes labelled GoodSleep, adjusts the room temperature gradually and reduces fan speed so the unit is less intrusive overnight. It can be used during auto, heat, dry, cool or fan operation.
Some Hitachi units include a motion sensor and a mode called SleepSense, which was previously named Air Sleep or iSense. It settles the room to a comfortable temperature to help you drop off, then fine tunes it once it senses you are asleep, which keeps the room steady and trims energy use at the same time.
Timer symbols
A clock or timer symbol means the unit has been told to switch itself on or off. Hitachi remotes offer an off timer, an on timer, and a combined on and off timer, and only one timer mode can be active at a time. If a weekly timer has been programmed, a simple on and off timer takes priority over it.
How you set it depends on your remote. Controllers with a clock let you choose the actual time. Controllers without one ask for a number of hours to count down instead.
If your air conditioner keeps turning itself on or off at odd moments, look for this symbol before assuming there is a fault. An unwanted timer is a far more common explanation than a failing control board.
Maintenance symbols, and what they are really telling you
The filter sign
The filter sign appears on the controller screen, on the unit itself, or on both, and it means it is time to clean the main filter. Hitachi notes that it usually appears after a set number of accumulated operating hours, so it is counting time rather than detecting dirt.
Treat it as a reminder, not a fault. Clean the filter, put it back, and reset the sign. A blocked filter is a common reason a healthy air conditioner stops cooling properly, so this small symbol saves more call outs than any other on the remote. It is also worth knowing how often you should service your air conditioner, because the filter sign only tracks the part you can clean yourself.
FrostWash and the Clean button
FrostWash is a Hitachi cleaning cycle that freezes and then defrosts the indoor heat exchanger to lift dust and dirt off it. You start it with the FrostWash or Clean button, and it only runs within certain temperature and humidity ranges.
A few rules come with it. Stop it with the on and off button if you need to. Once a cycle finishes it cannot be started again for about 60 minutes. Keep windows and doors closed while it runs, because outside air entering the room can cause condensation. Do not open the front panel during the cycle, and clear any timer settings before starting, since a timer will block it.
FrostWash will not remove every trace of dust and dirt, and it can make some unusual noises while it works. Neither of those is a fault.
Transmission and invalid operation signs
The transmission sign is a small mark that lights up when the remote sends a command. It is good news, and it tells you the remote is doing its job.
The invalid operation sign is the opposite. It appears when a command could not be completed or an unexpected error occurred. One flash of it means very little. Seeing it repeatedly is worth investigating, and the checks in the next section are the place to start.
What does the padlock symbol mean on a Hitachi remote?
A padlock, which Hitachi also calls prohibition, means the controls are locked and pressing buttons will not change anything. It is there to stop settings being altered by someone who should not be altering them.
There are two kinds. A complete lock, sometimes called a child lock, freezes every button. A partial lock restricts only selected controls, so an operation mode lock stops anybody changing between cooling and heating while still letting them adjust temperature and fan speed.
Unlocking almost always means pressing two specific buttons at the same time, but the combination varies between Hitachi controllers, including handheld remotes, wired controllers and app based ones. The operation manual for your particular controller is the reliable answer here.
There is also a deliberate mode lock you can set yourself. Pressing the mode button and the mode operation button together for about three seconds while the remote is off fixes the unit in heat, cool or dry. The same steps unlock it. It will not engage if a timer reservation or My Mode is already active.
Leave Home, the symbol most Australians never use
Leave Home is built for properties that sit empty in genuinely cold weather. It holds a minimum amount of heat in the house so the room temperature does not fall too far and the risk of pipes freezing is reduced.
It starts at 10 degrees and can be set between 10 and 16 degrees. Press the Leave Home button while the unit is on standby or running and heating begins at 10 degrees, after which you can adjust within that range. Cancel it with the on and off button, by pressing Leave Home again, or by choosing another mode. While it is running, fan speed and the air deflector cannot be changed.
In most of Melbourne this is a symbol you will never need. It is worth recognising all the same, because a unit left in Leave Home will appear to be heating very weakly and doing nothing else, which looks like a fault and is not one.
My Mode and personal settings
My Mode lets you save your own comfort settings on the remote, with up to three programs available on the models that offer it. If one person in the house likes strong cooling at 24 degrees with a high fan and somebody else prefers 26 degrees and a low fan, both can be stored and recalled with a single press.
It is only available on certain Hitachi residential models, so check your manual before hunting for it on the remote.
Why is my Hitachi air conditioner remote not working?
Before assuming the remote has failed, Hitachi suggests a short sequence of checks, and in practice most remotes come back to life somewhere in the middle of it.
- Take the batteries out, wait 30 seconds, and put them back in the right way around. This clears most glitches.
- Press any button and look at the sending end of the remote. If no light shows there, the remote itself may be faulty.
- Check nothing is blocking the path between the remote and the indoor unit. A cupboard door left open or a tall pot plant is enough.
- Look for bright light falling on the unit. Strong light can jam the signal, so dim it or move it and try again.
- If the display is frozen, press the reset key with something pointed such as a pen. The screen shows the default settings for two seconds and every setting returns to default apart from special functions you have activated.
If none of that helps, the fault is in the remote or in the receiver on the indoor unit, and that is a call worth making rather than a problem to keep poking at.
Which symbols point at a real fault?
Most symbols on a Hitachi remote describe a setting, not a problem. That is the reassuring part. A few situations are worth treating differently.
- The invalid operation sign keeps returning even after fresh batteries and a clear line of sight.
- A light on the indoor unit is flashing while the remote appears normal. A flashing indicator on the unit itself is the unit reporting something, not the remote.
- The correct mode is selected and the room still will not change temperature. Snowflake showing, temperature set below the room, filter clean, and nothing happens.
- Water appears where it should not be, on the wall below the unit or dripping from the indoor fascia.
- FrostWash refuses to run repeatedly even with timers cleared and the 60 minute wait observed.
Those five are worth a technician looking at. Everything else on this page is a setting you can change from the sofa.
One thing worth knowing about Hitachi in Australia
If you go looking for support and find yourself on a Bosch page, you have not taken a wrong turn. Hitachi Cooling and Heating products are manufactured and sold by Bosch Home Comfort Group, which holds a trademark licence from Hitachi. Documentation and warranty support for Australian owners sit within that arrangement, so both names appearing is normal.
Getting your Hitachi back to doing its job
Almost every symbol on a Hitachi remote is the unit telling you what it has been asked to do. A snowflake, a droplet, a padlock, a filter reminder. Read the chart at the top of this page, match what is on your screen, and most of the time the fix is a button press away.
When the symbols all look right and the room still will not behave, that is the point where guessing costs more than asking. We send a licensed technician who works on Hitachi split, multi head and ducted systems across Melbourne, and the price is confirmed before any work starts.
If you are weighing a replacement rather than decoding an existing unit, our guide to the best air conditioner brands in Australia compares the range sold here.
For your model’s manual and warranty details, see the official Hitachi Air Conditioning Australia website.
Need a technician for your Hitachi system? Read about our Hitachi air conditioner service in Melbourne, or call 03 9088 4796.
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Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles