Vaillant heating & air conditioning symbols
Vaillant: 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.
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
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
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
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
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
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