Skip to content 12 o’clock position: 24 °C (76 °F) COLD position: 18 °C (64 °F) HOT position: 30 °C (86 °F) ON Valve regulates hot air pressure. OFF Valve closes, and trim air valves close. FAULT circuit is reset. FAULT FAULT light comes on amber, along with an associated ECAM caution, when duct overheat is detected – temperature reaches 88 °C (190 °F). Valve and trim air valves close automatically. FAULT light goes off when the temperature drops below 70 °C (158 °F), and the flight crew selects OFF. ON Pack flow control valve is automatically controlled. OFF Pack flow control valve closes. FAULT Amber light and ECAM caution if the pack flow control valve position disagrees with the selected position, or in the case of compressor outlet overheat or pack outlet overheat. Permits the selection of pack valve flow, according to the number of passengers and ambient conditions (smoke removal, hot or wet conditions). LO – 80 % NORM – 100 % HI – 120 % On ground with both engines running, NORM flow is limited to 85 %. Manual selection is irrelevant in single pack operation, or with APU bleed supply. In these cases, HI is automatically selected. If LO is selected, the pack flow can automatically provide up to NORM flow (100 %) when the cooling demand cannot be satisfied. ON Emergency ram air inlet opens. If Δp ≥ 1 PSI: The outflow valve control remains normal. No emergency ram air flows in. If Δp < 1 PSI: The outflow valve opens to about 50% when under automatic control. It does not automatically open when it is under manual control. Emergency ram airflow is directly supplied to the mixer unit. When DITCHING is pressed this is closed. OFF Emergency ram air inlet closes. ON – Bleed valve opens and pressure is provided FAULT – Amber light and an ECAM caution if : Overpressure downstream of the bleed valve. Bleed air overheat. Wing or pylon leak on the related side. Bleed valve is not closed during engine start. Bleed valve is not closed with APU bleed ON. HP valve failed open on ground. Single BTS failure on ground or BTS disagree on ground. Dual BTS failure in flight or on ground. Fan Duct burst detected by the FADEC (LEAP-1A engines only). Fault light goes out when the ENG BLEED pb-sw is OFF if the fault has disappeared. OFF – Bleed valve, fan air valve and HP valve close. The white OFF light comes on. ON: APU valve opens if APU N >95 %. The blue ON light comes on. OFF: APU valve closes. FAULT: Amber light and an ECAM caution, when the system detects an APU leak. AUTO Crossbleed valve is open if the APU bleed valve is open. Crossbleed valve is closed if the APU bleed valve is closed or, in case of a wing, pylon, or APU leak (except during engine start). OPEN: Crossbleed valve is open. SHUT: Crossbleed valve is closed.