Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -r6d500da57b7590f105f7b39261af4321998d2175 -rf2cecb1dae0cfccc768b321f1d0cdec9a73c5824
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 6d500da57b7590f105f7b39261af4321998d2175)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision f2cecb1dae0cfccc768b321f1d0cdec9a73c5824)
@@ -256,7 +256,7 @@
             {
                 if ( DG_GEN_IDLE_MODE_STATE_FLUSH_WATER == dgSubMode )
                 {
-                    cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+                    cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE, FALSE );
                 }
             }
             else if ( DG_MODE_DRAI == dgOpMode )
@@ -928,13 +928,14 @@
  * @param tareLoadCell flag to tell DG tare load cell or not
  * @return none
  *************************************************************************/
-void cmdStartDGDrain( U32 drainToVolMl, BOOL tareLoadCell )
+void cmdStartDGDrain( U32 drainToVolMl, BOOL tareLoadCell, BOOL rinse )
 {
     DRAIN_RESERVOIR_CMD_PAYLOAD_T payload;
 
     dgCmdResp[ DG_CMD_START_DRAIN ].commandID = DG_CMD_NONE;
     payload.drainToVolumeML = drainToVolMl;
-    payload.tareLoadCells = tareLoadCell;
+    payload.tareLoadCells = tareLoadCell;
+    payload.rinseConcentrateLines = rinse;
     dgReservoirDrainVolumeTargetSet = drainToVolMl;
 
     sendDGDrainCommand( &payload );
Index: firmware/App/Controllers/DGInterface.h
===================================================================
diff -u -r3f2b9de757500da37e0ed8881e4e906d94f3076c -rf2cecb1dae0cfccc768b321f1d0cdec9a73c5824
--- firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision 3f2b9de757500da37e0ed8881e4e906d94f3076c)
+++ firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision f2cecb1dae0cfccc768b321f1d0cdec9a73c5824)
@@ -113,6 +113,7 @@
 {
     U32  drainToVolumeML;                           ///< Drain to target volume in ml
     BOOL tareLoadCells;                             ///< Flag indicates to tare load cells or not
+    BOOL rinseConcentrateLines;                     ///< Flag indicates to rinse concentrate lines or not
 } DRAIN_RESERVOIR_CMD_PAYLOAD_T;
 
 /// DG command response data record structure.
@@ -172,8 +173,8 @@
 void cmdSetDGActiveReservoir( DG_RESERVOIR_ID_T resID );
 void cmdChangeDGValveSetting( DG_VALVE_SETTING_ID_T valveSettingID );
 void cmdStartDGFill( U32 fillToVolMl );
-void cmdStopDGFill( void );
-void cmdStartDGDrain( U32 drainToVolMl, BOOL tareLoadCell );
+void cmdStopDGFill( void );
+void cmdStartDGDrain( U32 drainToVolMl, BOOL tareLoadCell, BOOL rinse );
 void cmdStartDGTrimmerHeater( void );
 void cmdStopDGTrimmerHeater( void );
 void cmdDGSampleWater( SAMPLE_WATER_CMD_T cmd );
Index: firmware/App/Modes/ModePostTreat.c
===================================================================
diff -u -rf5e2cabefb2f3d4757c150e9de136d5249b1e019 -rf2cecb1dae0cfccc768b321f1d0cdec9a73c5824
--- firmware/App/Modes/ModePostTreat.c	(.../ModePostTreat.c)	(revision f5e2cabefb2f3d4757c150e9de136d5249b1e019)
+++ firmware/App/Modes/ModePostTreat.c	(.../ModePostTreat.c)	(revision f2cecb1dae0cfccc768b321f1d0cdec9a73c5824)
@@ -63,7 +63,8 @@
 static BOOL disposableRemovalConfirmed = FALSE;                     ///< Flag indicates user confirms disposable removal.
 
 static BOOL isDrainStarted = FALSE;                                 ///< Flag indicates a drain operation has been started.
-static BOOL isDrainCompleted = FALSE;
+static BOOL isDrainCompleted = FALSE;                               ///< Flag indicates drain has completed.
+static BOOL rinseConcentrateLines = FALSE;                          ///< FLag indicates to rinse concentrate lines.
 
 static HD_POST_TREATMENT_STATE_T currentPostTreatmentState;         ///< Current state of post-treatment mode state machine.
 static DRAIN_STATE_T currentDrainReservoirState;                    ///< Current drain reservoir state.
@@ -100,6 +101,7 @@
     disposableRemovalConfirmed = FALSE;
     isDrainStarted = FALSE;
     isDrainCompleted = FALSE;
+    rinseConcentrateLines = FALSE;
     currentPostTreatmentState = HD_POST_TREATMENT_PATIENT_DISCONNECTION_STATE;
     currentDrainReservoirState = DRAIN_FIRST_RESERVOIR_START_STATE;
     postTreatmentPublishTimerCounter = 0;
@@ -510,7 +512,7 @@
         }
         else
         {
-            cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+            cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE, rinseConcentrateLines );
         }
     }
 
@@ -536,7 +538,8 @@
         if ( TRUE == hasDGCompletedReservoirSwitch() )
         {
             state = DRAIN_FIRST_RESERVOIR_STATE;
-            cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+            rinseConcentrateLines = FALSE;
+            cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE, rinseConcentrateLines );
         }
     }
 
@@ -595,7 +598,8 @@
     if ( TRUE == hasDGCompletedReservoirSwitch() )
     {
         state = DRAIN_SECOND_RESERVOIR_STATE;
-        cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+        rinseConcentrateLines = TRUE;
+        cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE, rinseConcentrateLines );
     }
 
     return state;
@@ -618,7 +622,7 @@
         isDrainStarted = TRUE;
     }
 
-    // Drain has started and DG goes to re-circ mode flush lines state means drain completed
+    // Drain has started and DG goes to generation idle mode flush lines state means drain completed
     if ( ( TRUE == isDrainStarted ) && ( DG_GEN_IDLE_MODE_STATE_FLUSH_LINES == getDGSubMode() ) )
     {
         isDrainCompleted = TRUE;
@@ -630,6 +634,7 @@
         {
             isDrainStarted = FALSE;
             isDrainCompleted = FALSE;
+            rinseConcentrateLines = FALSE;
             state = DRAIN_COMPLETE_STATE;
         }
     }
Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r6d500da57b7590f105f7b39261af4321998d2175 -rf2cecb1dae0cfccc768b321f1d0cdec9a73c5824
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 6d500da57b7590f105f7b39261af4321998d2175)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision f2cecb1dae0cfccc768b321f1d0cdec9a73c5824)
@@ -868,7 +868,7 @@
         if ( ( DG_MODE_GENE == dgOpMode ) && ( DG_GEN_IDLE_MODE_STATE_FLUSH_WATER == dgSubMode ) )
         {
             state = PRE_TREATMENT_RESERVOIR_MGMT_DRAIN_CMD_RESP_STATE;
-            cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+            cmdStartDGDrain( DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE, FALSE );
         }
     }