Index: firmware/App/Controllers/AirTrap.c
===================================================================
diff -u -r19a8bf98a7154e24c35da25225d4b55bf70ddd09 -rd710343a990811b05a23c81b4eaef3dd547c474a
--- firmware/App/Controllers/AirTrap.c	(.../AirTrap.c)	(revision 19a8bf98a7154e24c35da25225d4b55bf70ddd09)
+++ firmware/App/Controllers/AirTrap.c	(.../AirTrap.c)	(revision d710343a990811b05a23c81b4eaef3dd547c474a)
@@ -347,7 +347,7 @@
         result = AIR_TRAP_MANUAL_CONTROL_STATE;
     }
     // Transition to closed valve state when fluid detected at upper level
-    else if ( AIR_TRAP_LEVEL_FLUID == getAirTrapLevel( AIR_TRAP_LEVEL_SENSOR_UPPER ) )
+    else if ( AIR_TRAP_LEVEL_FLUID == getAirTrapLevel( AIR_TRAP_LEVEL_SENSOR_LOWER ) )
     {
         setValveAirTrap( STATE_CLOSED );
         result = AIR_TRAP_VALVE_CLOSED_STATE;