Boeing 737 NG Systems Review
Forward Overhead Panel  800/900
Display Selector
Bleed Air Panel 800/900
ISOLATION VALVE Switch


CLOSE – Closes the isolation valve.

AUTO –

  • Closes the isolation valve if both engine BLEED air
    switches are ON and both air conditioning PACK switches
    are in AUTO or HIGH

  • Opens the isolation valve automatically if either engine
    BLEED air or air conditioning PACK switch is positioned
    OFF.

OPEN – Opens the isolation valve.