Heating & air conditioning symbols
Symbols on air conditioner remotes and indoor-unit displays, dehumidifiers, electric and oil-filled heaters, and boiler displays: operating modes, fan and airflow settings, timers, comfort functions and status or fault indicators.
AUTO modeHeating & air conditioningAUTO modeThe air conditioner picks COOL or HEAT by itself from the room and outdoor temperatures, and re-checks at regular intervals to hold the set temperature. Set temperature range in AUTO: 18–30 °C. Selected by pressing the Mode button until this icon shows on the remote's display.On ARC466A9
Airflow rate: AutoHeating & air conditioningAirflow rate: AutoShown when the Fan button is set to Auto: the unit chooses the airflow rate itself. Pressing the Fan button steps through Auto, indoor unit quiet, then five fixed levels from low to high. In DRY mode the airflow rate cannot be changed.On ARC466A9
Anti-freezeHeating & air conditioningAnti-freezeAppears when the set temperature is lowered to 5 °C with the − button. The radiator then stays off and switches on at full power only if the room falls below 5 °C, to stop it freezing. Press + once to return to normal heating.On TRRS
Burner anti-cyclingHeating & air conditioningBurner anti-cyclingThe burner is waiting before it may light again. This pause avoids switching on and off too often and lengthens the boiler's life; no action is needed.On VU 446/5-5
Burner onHeating & air conditioningBurner onShown on the boiler display while the burner is lit and working correctly.On VU 446/5-5
COMFORT AIRFLOWHeating & air conditioningCOMFORT AIRFLOWDirects the air upward when cooling and downward when heating so it does not blow straight at people. Airflow rate is set to Auto, and choosing up and down swing cancels it. It cannot run together with POWERFUL; the last one selected wins. Selected with the Comfort/Sensor button.On ARC466A9
COOL modeHeating & air conditioningCOOL modeCools the room by moving its heat outdoors. Set temperature range: 18–32 °C; 26–28 °C is the suggested setting to save energy. Cooling performance can drop when it is very hot outside.On ARC466A9
Comfort dehumidifyingHeating & air conditioningComfort dehumidifyingButton and indicator for comfort dehumidifying. In this mode the humidity level cannot be set by hand; on some models pressing the up or down button cancels it.On MAD50C1AWS
ContinuousHeating & air conditioningContinuousButton and indicator for continuous operation: the dehumidifier keeps removing moisture without stopping at a target humidity. While it is on, the humidity setting is automatic and cannot be changed.On MAD50C1AWS
DRY modeHeating & air conditioningDRY modeRemoves humidity from the room while keeping the temperature as steady as possible. The unit controls temperature and airflow itself, so neither the set temperature nor the fan speed can be changed in this mode. Intended for indoor humidity up to 80 %; outside its operating range a safety device may stop the unit.On ARC466A9
Domestic hot waterHeating & air conditioningDomestic hot waterHot water production is active. Steady: hot water is being drawn but the burner is not yet lit. Flashing: the burner is on to heat the hot water.On VU 446/5-5
ECOHeating & air conditioningECOThe radiator chooses the most suitable power level itself to keep the room comfortable while using less energy, cycling down through the levels up to the one you selected (for example MAX–MED–MIN–OFF). If the room is far below the set temperature it heats up quickly first.On TRRS
ECONOHeating & air conditioningECONOCaps the air conditioner's maximum power use so it is less likely to trip a circuit breaker when other high-power appliances run at the same time. Works in AUTO, COOL, DRY and HEAT, only while the unit is running, and cannot be combined with POWERFUL. If power use is already low it has no effect.On ARC466A9
FAN modeHeating & air conditioningFAN modeRuns only the indoor fan to circulate air, without cooling or heating. The set temperature cannot be changed in this mode.On ARC466A9
FaultHeating & air conditioningFaultReplaces the normal display when the boiler has a fault, together with a fault code (F. and a number) and sometimes a plain-text message. If the fault cannot be cleared, contact a competent heating engineer; after an ignition fault (F.28 or F.29) check the gas valve is open and press reset, at most three times.On VU 446/5-5
Filter (clean filter reminder)Heating & air conditioningFilter (clean filter reminder)The filter light comes on after 250 hours of running as a reminder to clean the air filter. After cleaning, press the Filter button: the light goes out and the 250-hour count starts again. Cleaning the filter about every two weeks is recommended.On MAD50C1AWS
HEAT modeHeating & air conditioningHEAT modeHeats the room with the heat pump, taking heat from the outdoor air. Set temperature range: 10–30 °C (20–24 °C suggested). It takes a while before the room warms up, and heating capacity falls when it is cold outside. When frost builds up on the outdoor unit the system defrosts it, and no warm air comes out during that time; when the set temperature is reached heating stops but the indoor fan keeps running.On ARC466A9
Heating indicatorHeating & air conditioningHeating indicatorShows whether the radiator is heating, by colour: red at maximum power, orange at medium, green at minimum. When the icon is absent the radiator is not heating at that moment.On TRRS
Heating modeHeating & air conditioningHeating modeCentral heating is active. Steady: there is a heat demand from the heating. Flashing: the burner is on for the heating.On VU 446/5-5
Heating system filling pressureHeating & air conditioningHeating system filling pressureShows the current water pressure in the heating system; the dotted lines mark the permitted range. Steady: pressure is within range. Flashing: pressure is outside the range. Recommended filling pressure is 1.5–2.5 bar; below 0.5 bar the boiler switches off and shows fault F.22. If the pressure is too low, top up the heating system.On VU 446/5-5
INTELLIGENT EYEHeating & air conditioningINTELLIGENT EYEAn infrared sensor watches for people. The louvers steer the air towards areas where nobody is detected, and if no one is seen for 20 minutes the unit switches to energy saving: 2 °C lower in HEAT, 2 °C higher in COOL and DRY (1 °C above 30 °C room temperature), slightly less airflow in FAN. Can be combined with COMFORT AIRFLOW.On ARC466A9
Indoor unit quietHeating & air conditioningIndoor unit quietOne of the Fan button settings: the indoor fan runs at a weak airflow so the indoor unit is quieter. If the room does not reach the set temperature, choose a higher airflow setting.On ARC466A9
Key lockHeating & air conditioningKey lockPrevents accidental button presses. With the radiator on, hold + and − together for at least 3 seconds; the padlock appears and two beeps sound. Repeat the same to unlock.On TRRS
Maintenance requiredHeating & air conditioningMaintenance requiredThe boiler needs maintenance work but is not in fault and keeps running normally. Contact a competent heating engineer. If the water pressure is flashing at the same time, top up the heating water. Details of the message are in the boiler's status display (Live Monitor).On VU 446/5-5
OUTDOOR UNIT QUIETHeating & air conditioningOUTDOOR UNIT QUIETLowers the noise of the outdoor unit by reducing its compressor frequency and fan speed, useful at night for neighbours. Available in COOL, HEAT and AUTO only, not with POWERFUL. The icon stays on the remote display even after the unit is switched off.On ARC466A9
POWERFULHeating & air conditioningPOWERFULGives maximum cooling or heating capacity for 20 minutes, then returns to the previous settings. In COOL and HEAT the airflow is fixed at maximum and temperature and airflow cannot be changed; in AUTO the airflow is also fixed at maximum; in DRY the set temperature drops by 2.5 °C and airflow rises slightly; in FAN the airflow is fixed at maximum. It only works while the unit is running and cannot be combined with ECONO, COMFORT AIRFLOW or OUTDOOR UNIT QUIET.On ARC466A9
Power level (MIN / MED / MAX)Heating & air conditioningPower level (MIN / MED / MAX)Power button and display bars. Press to choose minimum (one bar), medium (two bars) or maximum (three bars) heat output. In ECO mode the chosen level is the highest the radiator will use.On TRRS
PumpHeating & air conditioningPumpButton and indicator for pump draining on models with a built-in pump. Fit the pump drain hose and remove the normal drain hose first; the pump then empties the bucket when it fills. Do not use the pump when the outdoor temperature is 0 °C or lower.On MAD50C1AWS
Right and left swingHeating & air conditioningRight and left swingShown when the louvers (vertical blades) swing left and right. Combined with the up and down swing the flaps and louvers move in turn (3-D airflow), which mixes cool air near the floor and warm air near the ceiling. Press the button again to stop the louvers in the current position.On ARC466A9
Standby (plug)Heating & air conditioningStandby (plug)Shown when the radiator is plugged in but not heating (standby). It always comes back in standby after a power cut or after being unplugged. Press the on/standby button to start heating.On TRRS
Summer modeHeating & air conditioningSummer modeHeating is switched off while hot water production stays available. Appears after the heating flow temperature is set to Heating off.On VU 446/5-5
Timer on/offHeating & air conditioningTimer on/offSets an automatic start or stop up to 24 hours ahead (0.5-hour steps up to 10 hours, then 1-hour steps). With the unit running, the first press sets Timer OFF and a second press Timer ON; with the unit off the order is reversed. Switching the unit on or off, or setting 0.0, cancels the timer.On MAD50C1AWS
TurboHeating & air conditioningTurboSwitches between turbo and normal fan speed; the high fan indicator shows when turbo is on. Use turbo for the fastest moisture removal and switch it off once the room is at the humidity you want.On MAD50C1AWS
Up and down swingHeating & air conditioningUp and down swingShown when the flaps (horizontal blades) swing up and down to spread the airflow. Press the swing button again when the flaps are where you want them to stop them there. Always move the flaps with the remote, never by hand.On ARC466A9