Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r65586d515b6824115a90d81595915be02213f679 -rab96bebce5f0d52588789be480d71a89b6811e2b
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 65586d515b6824115a90d81595915be02213f679)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision ab96bebce5f0d52588789be480d71a89b6811e2b)
@@ -111,6 +111,8 @@
  *************************************************************************/
 U32 transitionToStandbyMode( void )
 {
+    HD_OP_MODE_T previousOpMode = getPreviousOperationMode();
+
     // Re-initialize when transitioning to standby mode
     initStandbyMode();
     initDGInterface();
@@ -137,6 +139,12 @@
     setValvePosition( VBA, VALVE_POSITION_A_INSERT_EJECT );
     setValvePosition( VBV, VALVE_POSITION_A_INSERT_EJECT );
 
+    // If we just exited Post Treatment Mode, goto disinfect sub state.
+    if ( MODE_POST == previousOpMode )
+    {
+        currentStandbyState = STANDBY_WAIT_FOR_DISINFECT_STATE;
+    }
+
     return currentStandbyState;
 }