Index: firmware/App/Modes/FPModes/FlushPermeate.c
===================================================================
diff -u -rd79faa7118db6d048ce3433224b3e5a478c97a98 -rf73c82e967797bb1db745ebffd71a49e523e651c
--- firmware/App/Modes/FPModes/FlushPermeate.c	(.../FlushPermeate.c)	(revision d79faa7118db6d048ce3433224b3e5a478c97a98)
+++ firmware/App/Modes/FPModes/FlushPermeate.c	(.../FlushPermeate.c)	(revision f73c82e967797bb1db745ebffd71a49e523e651c)
@@ -19,9 +19,9 @@
 #include "Conductivity.h"
 #include "FlushPermeate.h"
 #include "FPOperationModes.h"
+#include "Level.h"
 #include "MessageSupport.h"
 #include "Messaging.h"
-#include "PermeateTank.h"
 #include "Pressure.h"
 #include "ROPump.h"
 #include "TaskGeneral.h"
@@ -35,13 +35,14 @@
 
 // ********** private definitions **********
 
-#define PERMEATE_FLUSH_MAX_TIMEOUT                  ( 600 * MS_PER_SECOND )                     ///< Max override timeout for 10 minutes
+#define PERMEATE_FLUSH_MAX_TIMEOUT                  ( 10 * SEC_PER_MIN * MS_PER_SECOND )        ///< Max override timeout for 10 minutes
 #define PERMEATE_FLUSH_DATA_PUBLISH_INTERVAL        ( MS_PER_SECOND / TASK_GENERAL_INTERVAL )   ///< Interval (ms/task time) at which the gen water mode data published.
-#define PERMEATE_FLUSH_TIMEOUT                      ( 120 * MS_PER_SECOND )                     ///< Permeate flush timer (in ms)
-#define PERMEATE_FLUSH_ALARM_TIMEOUT                ( 180 * MS_PER_SECOND )                     ///< Permeate flush alarm timer (in ms)
+#define PERMEATE_FLUSH_TIMEOUT                      ( 2 * SEC_PER_MIN * MS_PER_SECOND )         ///< Permeate flush timer (in ms) timeout for 2 minutes
+#define PERMEATE_FLUSH_ALARM_TIMEOUT                ( 5 * SEC_PER_MIN * MS_PER_SECOND )         ///< Permeate flush alarm timer (in ms) timeout for 5 minutes
 #define PERMEATE_FLUSH_RO_PUMP_TGT_ML               700                                         ///< Pressure target in ml/min for the RO pump during permeate flush.
 #define PERMEATE_FLUSH_BOOST_PUMP_TGT_PSI           25                                          ///< Pressure target in PSI for the boost pump during permeate flush.
 #define PERMEATE_FLUSH_CONDUCTIVITY_THRESHOLD       200.0F                                      ///< Conductivity alarm threshold for permeate flush.
+#define MIN_BOOST_PUMP_DUTY_CYCLE_PCT               0.5F                                        ///< Minimum duty cycle value for boost pump during open loop control
 
 // ********** private data **********
 
@@ -54,6 +55,7 @@
 static U32 permeateFlushAlarmTimer;
 static BOOL pendingStartPermeateFlushRequest;                                                   ///< signal to start flushing.
 static BOOL isFlushComplete;                                                                    ///< Permeate Flush complete BOOL
+static BOOL isTankFilled;                                                                       ///< Permeate tank filled in permeate flush state
 
 // ********** private function prototypes **********
 
@@ -92,6 +94,7 @@
     permeateFlushAlarmTimer                          = 0;
     isFlushComplete                                  = FALSE;
     pendingStartPermeateFlushRequest                 = FALSE;
+    isTankFilled                                     = FALSE;
 }
 
 /*********************************************************************//**
@@ -141,25 +144,51 @@
 static FP_PERM_FLUSH_STATE_T handlePermeateFlushProgressState( void )
 {
     FP_PERM_FLUSH_STATE_T state = PERM_FLUSH_IN_PROGRESS;
+    LEVEL_STATE_T level = getLevelStatus( P25_LEVL );
 
 //    if ( TRUE == 1 ))// TODO Alarm and Stop State Rework
 //    {
 //        state = PERM_FLUSH_PAUSED;
 //    }
 
-    if( TRUE == didTimeout( permeateFlushTimer, getPermeateFlushTimeout() ) )
+    // Manual control of Permeate tank while in Permeate Flush
+    // to prevent overfill.
+    if ( LEVEL_STATE_HIGH == level )
     {
+        setValveState( M4_VALV, VALVE_STATE_CLOSED );
+        if ( TRUE == isBoostPumpInstalled() )
+        {
+            // TODO update the default min duty cycle value after testing
+            F32 currentDutyCyclePct = getCurrentBoostPumpDutyCyclePCT() > MIN_BOOST_PUMP_DUTY_CYCLE_PCT ? getCurrentBoostPumpDutyCyclePCT(): MIN_BOOST_PUMP_DUTY_CYCLE_PCT;
+
+            setBoostPumpTargetDutyCycle( currentDutyCyclePct );
+            isTankFilled = TRUE;
+        }
+    }
+    else if ( LEVEL_STATE_LOW == level )
+    {
+        setValveState( M4_VALV, VALVE_STATE_OPEN );
+        // set boost pump to closed loop when M4 closed. Added Tank fill check to avoid reset during initial transition
+        if ( ( TRUE == isBoostPumpInstalled() ) && ( TRUE == isTankFilled ) )
+        {
+            setBoostPumpTargetPressure( PERMEATE_FLUSH_BOOST_PUMP_TGT_PSI );
+            isTankFilled = FALSE;
+        }
+    }
+
+    if ( TRUE == didTimeout( permeateFlushTimer, getPermeateFlushTimeout() ) )
+    {
         F32 p18conductivity = getFilteredConductivity( P18_COND );
-        if( PERMEATE_FLUSH_CONDUCTIVITY_THRESHOLD > p18conductivity )
+        if ( ( PERMEATE_FLUSH_CONDUCTIVITY_THRESHOLD > p18conductivity ) && ( LEVEL_STATE_HIGH == level ) )
         {
             isFlushComplete = TRUE;
             state = PERM_FLUSH_PAUSED;
         }
 
-        // If conductivity is not in range, continue to monitor until timeout
+        // If conductivity is not in range, continue to monitor until timeout, TODO if conductivity fluctuates for another 3 minutes
         else
         {
-            if( TRUE == didTimeout( permeateFlushAlarmTimer, getPermeateFlushAlarmTimeout() ) )
+            if ( TRUE == didTimeout( permeateFlushAlarmTimer, getPermeateFlushAlarmTimeout() ) )
             {
                 SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_PERMEATE_FLUSH_CONDUCTIVITY_TIMEOUT, PERMEATE_FLUSH_CONDUCTIVITY_THRESHOLD, p18conductivity)
                 state = PERM_FLUSH_PAUSED;
@@ -215,7 +244,6 @@
             setValveState( P34_VALV, VALVE_STATE_CLOSED );
             setValveState( P37_VALV, VALVE_STATE_CLOSED );
             setValveState( P39_VALV, VALVE_STATE_OPEN );
-            startPermeateTankControl();
             if ( TRUE == isBoostPumpInstalled() )
             {
                 setBoostPumpTargetPressure( PERMEATE_FLUSH_BOOST_PUMP_TGT_PSI );
@@ -239,7 +267,6 @@
                 setValveState( P34_VALV, VALVE_STATE_CLOSED );
                 setValveState( P37_VALV, VALVE_STATE_CLOSED );
                 setValveState( P39_VALV, VALVE_STATE_CLOSED );
-
                 if ( TRUE == isBoostPumpInstalled() )
                 {
                     signalBoostPumpHardStop();