Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -rb3034747b23029d9ab2b63cf5029f0bf54cf7bb9 -rf9a4906ada0b1ff467c23eb1e44784e343bdeca8
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision b3034747b23029d9ab2b63cf5029f0bf54cf7bb9)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision f9a4906ada0b1ff467c23eb1e44784e343bdeca8)
@@ -44,6 +44,7 @@
 /// Wait time for ui to transition on completion of a sub-mode (ms/task time).
 #define SUBMODE_COMPLETE_UI_TRANSITION_TIME_COUNT       ( MS_PER_SECOND / TASK_GENERAL_INTERVAL )
 #define DIP_PATIENT_CONNECTION_FLOW_RATE_ML_MIN         250             ///< Patient connection sub-mode dialysate inlet pump flow rate in mL/min.
+#define PRE_TREATMENT_HEATING_DIA_FLOW_ML_PER_MIN       600             ///< Pre treatment heating parameters dialysate flow in mL/min.
 
 #define PRE_TREATMENT_MIN_FILL_RESERVOIR_VOLUME_ML      125             ///< Fill reservoir to this volume minimum to prep volume during development.
 #define PRE_TREATMENT_FLUSH_RESERVOIR_VOLUME_ML         500             ///< Fill reservoir to this volume (in mL) to flush filter and lines.
@@ -129,6 +130,7 @@
 static PRE_TREATMENT_RESERVOIR_MGMT_STATE_T handlePreTreatmentReservoirMgmtRequestReservoirSwitchState( void );
 static PRE_TREATMENT_RESERVOIR_MGMT_STATE_T handlePreTreatmentReservoirMgmtWaitReservoirSwitchState( void );
 static U32 getPreTreatmentFillVolume( DG_RESERVOIR_ID_T inactiveRes );
+static void setPreTreatmentHeatingParams( U32 targetVolML, F32 targetFillFlowLPM, U32 dialysateFlowMLPM );
 
 /*********************************************************************//**
  * @brief
@@ -192,9 +194,6 @@
 
     initPreTreatmentMode();
 
-    // Set the heaters specs to start heating up the water
-    setDialysateHeatingParams();
-
     cmdStopDGTrimmerHeater();
 
     // Pumps should be off
@@ -1107,6 +1106,8 @@
     DG_RESERVOIR_ID_T inactiveReservoir = getDGInactiveReservoir();
     DG_OP_MODE_T dgOpMode = getDGOpMode();
     U32 dgSubMode = getDGSubMode();
+    U32 dialysateFlowMLPM = ( HD_PRE_TREATMENT_RECIRCULATE_STATE == currentPreTreatmentState ? DIP_PATIENT_CONNECTION_FLOW_RATE_ML_MIN :
+                                                                                               PRE_TREATMENT_HEATING_DIA_FLOW_ML_PER_MIN );
 
     if ( ( DG_MODE_GENE == dgOpMode ) && ( DG_GEN_IDLE_MODE_STATE_FLUSH_WATER == dgSubMode ) )
     {
@@ -1127,12 +1128,14 @@
              ( TRUE == reservoirStatus[ inactiveReservoir ].startFlushFill ) )
         {
             cmdStartDGFill( volume, DEFAULT_TARGET_FILL_FLOW_RATE_LPM );
+            setPreTreatmentHeatingParams( volume, DEFAULT_TARGET_FILL_FLOW_RATE_LPM, dialysateFlowMLPM );
             state = PRE_TREATMENT_RESERVOIR_MGMT_FILL_CMD_RESP_STATE;
         }
         else if ( ( TRUE == reservoirStatus[ inactiveReservoir ].flushComplete ) &&
                   ( TRUE == reservoirStatus[ inactiveReservoir ].startNormalFill ) )
         {
             cmdStartDGFill( volume, DEFAULT_TARGET_FILL_FLOW_RATE_LPM );
+            setPreTreatmentHeatingParams( volume, DEFAULT_TARGET_FILL_FLOW_RATE_LPM, dialysateFlowMLPM );
             state = PRE_TREATMENT_RESERVOIR_MGMT_FILL_CMD_RESP_STATE;
         }
     }
@@ -1364,6 +1367,31 @@
      return volume;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The setPreTreatmentHeatingParams function calculates and set the heating
+ * parameters to be sent to DG.
+ * @details Inputs: none
+ * @details Outputs: none
+ * @param targetVolML target fill volume in milliliters
+ * @param targetFillFlowLPM target fill flow rate in L/min
+ * @param dialysateFlowMLPM dialysate flow in mL/min
+ * @return none
+ *************************************************************************/
+static void setPreTreatmentHeatingParams( U32 targetVolML, F32 targetFillFlowLPM, U32 dialysateFlowMLPM )
+{
+    DG_CMD_DIALYSATE_HEATING_PARAMS_T params;
+    F32 fillTimeMS = ( (F32)targetVolML / ( targetFillFlowLPM * ML_PER_LITER ) ) * SEC_PER_MIN * MS_PER_SECOND;
+
+    params.trimmerTargetTemperature   = getTreatmentParameterF32( TREATMENT_PARAM_DIALYSATE_TEMPERATURE );
+    params.timeReservoirWait2SwitchMS = 0;
+    params.timeReservoirFillMS        = fillTimeMS;
+    params.timeReservoirCycleMS       = (U32)fillTimeMS;
+    params.dialysateFlowLPM           = ( (F32)dialysateFlowMLPM ) / ML_PER_LITER;
+
+    cmdSetDGDialysateHeatingParams( params );
+}
+
 /*************************************************************************
  *                       TEST SUPPORT FUNCTIONS
  *************************************************************************/