Index: firmware/App/Modes/ModeDrain.c
===================================================================
diff -u -r26f63d0260a3c35277e3e6dbca3573c253775318 -r1b95ae077de1d01a314be8cc011662ab508fba10
--- firmware/App/Modes/ModeDrain.c	(.../ModeDrain.c)	(revision 26f63d0260a3c35277e3e6dbca3573c253775318)
+++ firmware/App/Modes/ModeDrain.c	(.../ModeDrain.c)	(revision 1b95ae077de1d01a314be8cc011662ab508fba10)
@@ -15,6 +15,7 @@
 *
 ***************************************************************************/
 
+#include "ConcentratePumps.h"
 #include "ConductivitySensors.h"
 #include "DrainPump.h"
 #include "Heaters.h"
@@ -49,16 +50,24 @@
 
 #define DIALYSATE_DRAIN_TIME_OUT        ( 2 * SEC_PER_MIN * MS_PER_SECOND )                   ///< Dialysate drain time out.
 
+/// Time period to wait for concentrate lines to rinse.
+#define RINSE_CONCENTRATE_LINES_WAIT    ( 25 * MS_PER_SECOND / TASK_GENERAL_INTERVAL )
+/// Reserver the concentrate speed to rinse out concentrate lines.
+#define RINSE_SPEED                     ( ( CONCENTRATE_PUMP_MAX_SPEED - 3.0 ) * -1.0 )
+
 // ********** private data **********
 
 static DG_DRAIN_STATE_T drainState;                                                           ///< Currently active drain state.
 static U32 drainEmptyTareTimerCtr;                                                            ///< Timer counter for delay between drain complete and load cell tare.
 static U32 dialysateDrainStartTime;                                                           ///< Dialysate drain start time.
+static BOOL rinseConcentrateLines;                                                            ///< Flag indicates to rinse concentrate lines.
+static U32 rinseConcentrateLinesTimerCtr;                                                     ///< Timer counter for rinsing concentrate lines.
 
 // ********** private function prototypes **********
 static DG_DRAIN_STATE_T handleDrainStateStart( void );
 static DG_DRAIN_STATE_T handleDrainStateDrain( void );
 static DG_DRAIN_STATE_T handleDrainStateTare( void );
+static DG_DRAIN_STATE_T handleRinseState( void );
 
 /*********************************************************************//**
  * @brief
@@ -69,9 +78,11 @@
  *************************************************************************/
 void initDrainMode( void )
 {
-    drainState              = DG_DRAIN_STATE_START;
-    drainEmptyTareTimerCtr  = 0;
-    dialysateDrainStartTime = 0;
+    drainState                    = DG_DRAIN_STATE_START;
+    drainEmptyTareTimerCtr        = 0;
+    dialysateDrainStartTime       = 0;
+    rinseConcentrateLines         = FALSE;
+    rinseConcentrateLinesTimerCtr = 0;
 }
 
 /*********************************************************************//**
@@ -141,6 +152,10 @@
             drainState = handleDrainStateTare();
             break;
 
+        case DG_DRAIN_STATE_RINSE:
+            drainState = handleRinseState();
+            break;
+
         default:
             SET_ALARM_WITH_2_U32_DATA( ALARM_ID_DG_SOFTWARE_FAULT, SW_FAULT_ID_DRAIN_MODE_INVALID_EXEC_STATE, drainState )
             drainState = DG_DRAIN_STATE_START;
@@ -152,6 +167,30 @@
 
 /*********************************************************************//**
  * @brief
+ * The getCurrentDrainState function returns the current state of the drain mode.
+ * @details Inputs: drainState
+ * @details Outputs: none
+ * @return the current state of drain mode.
+ *************************************************************************/
+DG_DRAIN_STATE_T getCurrentDrainState( void )
+{
+    return drainState;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The signalDrainModeRinseConcentrateLines function sets the flag for drain
+ * mode to rinse concentrate lines.
+ * @details Inputs: none
+ * @details Outputs: rinseConcentrateLines
+ * @return none
+ *************************************************************************/
+void signalDrainModeRinseConcentrateLines( BOOL rinse )
+{
+    rinseConcentrateLines = rinse;
+}
+
+/*********************************************************************//**
  * The handleDrainStateStart function handles the drain start state of
  * the drain mode state machine.
  * @details Inputs: none
@@ -187,7 +226,7 @@
     // if we have reached our target drain to volume (by weight) or cannot drain anymore, we are done draining - go back to generation idle mode
     if ( TRUE == hasTargetDrainVolumeBeenReached( inactiveReservoir, DRAIN_WEIGHT_UNCHANGE_TIMEOUT ) )
     {
-        setDrainPumpTargetRPM( 0 );
+        signalDrainPumpHardStop();
 
         if ( DG_RESERVOIR_1 == inactiveReservoir )
         {
@@ -234,25 +273,52 @@
     {
         drainEmptyTareTimerCtr = 0;
         tareLoadCellsAtEmpty( inactiveReservoir );
-        requestNewOperationMode( DG_MODE_GENE );
 
         setValveState( VRD1, VALVE_STATE_CLOSED );
         setValveState( VRD2, VALVE_STATE_CLOSED );
+
+        if ( TRUE == rinseConcentrateLines )
+        {
+            setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP1_ACID, RINSE_SPEED );
+            setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP2_BICARB, RINSE_SPEED );
+            requestConcentratePumpOn( CONCENTRATEPUMPS_CP1_ACID );
+            requestConcentratePumpOn( CONCENTRATEPUMPS_CP2_BICARB );
+        }
+        rinseConcentrateLinesTimerCtr = 0;
+        result = DG_DRAIN_STATE_RINSE;
     }
 
     return result;
 }
 
 /*********************************************************************//**
  * @brief
- * The getCurrentDrainState function returns the current state of the drain mode.
- * @details Inputs: drainState
- * @details Outputs: none
- * @return the current state of drain mode.
+ * The handleRinseState function handles the tare state of the drain mode
+ * state machine.
+ * @details Inputs: drainEmptyTareTimerCtr
+ * @details Outputs: drainEmptyTareTimerCtr
+ * @return the next state
  *************************************************************************/
-DG_DRAIN_STATE_T getCurrentDrainState( void )
+static DG_DRAIN_STATE_T handleRinseState( void )
 {
-    return drainState;
+    DG_DRAIN_STATE_T result = DG_DRAIN_STATE_RINSE;
+
+    if ( TRUE == rinseConcentrateLines )
+    {
+        if ( ++rinseConcentrateLinesTimerCtr > RINSE_CONCENTRATE_LINES_WAIT )
+        {
+            rinseConcentrateLinesTimerCtr = 0;
+            requestConcentratePumpOff( CONCENTRATEPUMPS_CP1_ACID );
+            requestConcentratePumpOff( CONCENTRATEPUMPS_CP2_BICARB );
+            requestNewOperationMode( DG_MODE_GENE );
+        }
+    }
+    else
+    {
+        requestNewOperationMode( DG_MODE_GENE );
+    }
+
+    return result;
 }
 
 /**@}*/