Index: firmware/App/Modes/ModeTreatment.c
===================================================================
diff -u -r8cf0fafa78ce14b5dbdf95510e957846660ac2b9 -r32309398e7ef59471bd624e34ab6b91cdaaf9d24
--- firmware/App/Modes/ModeTreatment.c	(.../ModeTreatment.c)	(revision 8cf0fafa78ce14b5dbdf95510e957846660ac2b9)
+++ firmware/App/Modes/ModeTreatment.c	(.../ModeTreatment.c)	(revision 32309398e7ef59471bd624e34ab6b91cdaaf9d24)
@@ -74,6 +74,24 @@
 /// Macro to calculate the remaining treatment time in seconds.
 #define CALC_TREAT_TIME_REMAINING_IN_SECS()     ( (S32)presTreatmentTimeSecs - (S32)( treatmentTimeMS / MS_PER_SECOND ) )
 
+#define DPI_TO_BLD_VOLUME_ML        ( 3.07F + 12.28F )      ///< Dialysate inlet pump to blood detect sensor volume in milliliters.
+
+typedef enum BloodLeakZeroingState
+{
+    BLD_ZEROING_FLUSH = 0,
+    BLD_ZEROING_ZERO,
+    BLD_ZEROING_VERIFY_SEQ,
+    BLD_ZEROING_VERIFY_INTENSITY,
+    BLD_ZEROING_COMPLETE,
+    NUM_OF_BLD_ZEROING
+} BLOOD_LEAK_ZEROING_STATE_T;
+
+typedef struct
+{
+    F32 DPiToBLDFlushedVolML;
+    BLOOD_LEAK_ZEROING_STATE_T bloodLeakZeroingState;
+} BLOOD_LEAK_ZEROING_T ;
+
 // ********** private data **********
 
 static TREATMENT_STATE_T currentTreatmentState;                 ///< Current state (sub-mode) of treatment mode.
@@ -132,6 +150,8 @@
 static U32 treatmentStartTimeStamp;                             ///< Treatment start timestampt for logging purpose.
 static U32 treatmentEndTimeStamp;                               ///< Treatment end timestampt for logging purpose.
 
+static BLOOD_LEAK_ZEROING_T bloodLeakZeroing;
+
 // ********** private function prototypes **********
 
 static void broadcastTreatmentSettingsRanges( void );
@@ -146,6 +166,7 @@
 static TREATMENT_STATE_T handleTreatmentEndState( void );
 static void resetSignalFlags( void );
 static void resetAlarmSignalFlags( void );
+static BOOL hasDPiToBLDVolumeBeenFlushed( void );
 
 /*********************************************************************//**
  * @brief
@@ -1501,6 +1522,62 @@
     }
 }
 
+void handleBloodLeakZeroing( void )
+{
+    BOOL status = FALSE;
+
+    switch( bloodLeakZeroing.bloodLeakZeroingState )
+    {
+        case BLD_ZEROING_FLUSH:
+            status                                 = hasDPiToBLDVolumeBeenFlushed();
+            bloodLeakZeroing.bloodLeakZeroingState = ( TRUE == status ? BLD_ZEROING_ZERO : BLD_ZEROING_FLUSH );
+            break;
+
+        case BLD_ZEROING_ZERO:
+            status                                 = zeroBloodLeak();
+            bloodLeakZeroing.bloodLeakZeroingState = ( TRUE == status ? BLD_ZEROING_VERIFY_SEQ : BLD_ZEROING_ZERO );
+            break;
+
+        case BLD_ZEROING_VERIFY_SEQ:
+        {
+            SELF_TEST_STATUS_T status = getBloodLeakSelfTestStatus();
+
+            if ( SELF_TEST_STATUS_PASSED == status )
+            {
+                bloodLeakZeroing.bloodLeakZeroingState = BLD_ZEROING_VERIFY_INTENSITY;
+            }
+            else if ( SELF_TEST_STATUS_FAILED == status )
+            {
+                if ( TRUE == hasBloodLeakZeroSequenceFailed() )
+                {
+                    activateAlarmNoData( ALARM_ID_HD_BLOOD_LEAK_SENSOR_ZERO_SEQUENCE_FAILED );
+                }
+                else
+                {
+                    bloodLeakZeroing.bloodLeakZeroingState = BLD_ZEROING_ZERO;
+                }
+            }
+        }
+            break;
+
+        case BLD_ZEROING_VERIFY_INTENSITY:
+            if ( BLOOD_LEAK_INTENSITY_IN_RANGE == getBloodLeakIntensityStatusAfterZeroing() )
+            {
+                bloodLeakZeroing.bloodLeakZeroingState = BLD_ZEROING_COMPLETE;
+            }
+            else
+            {
+                // TODO can we try intensity for 3 times too?
+                // TODO alarm for intensity failure
+            }
+            break;
+
+        default:
+            // TODO software fault
+            break;
+    }
+}
+
 /*********************************************************************//**
  * @brief
  * The broadcastTreatmentSettingsRanges function computes and broadcasts
@@ -1658,7 +1735,23 @@
     endTreatmentAlarmResponseRequest = FALSE;
 }
 
+static BOOL hasDPiToBLDVolumeBeenFlushed( void )
+{
+    BOOL status                   = FALSE;
+    F32 targetDPiMLPM             = (F32)abs( getTargetDialInFlowRate() );
+    F32 measuredDPiMLPM           = getMeasuredDialInFlowRate();
+    BOOL hasTargetFlowBeenReached = ( fabs( targetDPiMLPM - measuredDPiMLPM ) < NEARLY_ZERO );
 
+    if ( TRUE == hasTargetFlowBeenReached )
+    {
+        bloodLeakZeroing.DPiToBLDFlushedVolML += ( measuredDPiMLPM * TASK_GENERAL_INTERVAL ) / ( SEC_PER_MIN * MS_PER_SECOND );
+        status                                 = ( ( bloodLeakZeroing.DPiToBLDFlushedVolML - DPI_TO_BLD_VOLUME_ML ) < NEARLY_ZERO ? TRUE : FALSE );
+        bloodLeakZeroing.DPiToBLDFlushedVolML  = 0.0F;
+    }
+
+    return status;
+}
+
 /*************************************************************************
  *                       TEST SUPPORT FUNCTIONS
  *************************************************************************/