Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -ra5e4e578efe1af6c82530e73d58b09b2b7ad625c -r8272c6f212023b3f591454c609088be36a6f5980
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision a5e4e578efe1af6c82530e73d58b09b2b7ad625c)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 8272c6f212023b3f591454c609088be36a6f5980)
@@ -70,12 +70,13 @@
 /// Fill conditions status
 typedef struct
 {
-    F32 fillFlowRateRunningSum;                                             ///< Fill flow running sum.
-    U32 fillSampleCounter;                                                  ///< Fill flow sample counter.
-    F32 fillTemperatureRunningSum;                                          ///< Fill temperature running sum.
-    F32 fillTemperatureAverage;                                             ///< Fill temperature average value.
-    F32 fillFlowRateAverage;                                                ///< Fill flow average value.
-    F32 fillLastTemperature;                                                ///< Fill last temperature value.
+    F32  fillFlowRateRunningSum;                                                                             ///< Fill flow running sum.
+    U32  fillSampleCounter;                                                                                  ///< Fill flow sample counter.
+    F32  fillTemperatureRunningSum;                                                                          ///< Fill temperature running sum.
+    F32  fillTemperatureAverage;                                                                             ///< Fill temperature average value.
+    F32  fillFlowRateAverage;                                                                                ///< Fill flow average value.
+    F32  fillLastTemperature;                                                                                ///< Fill last temperature value.
+    BOOL isThisFirstFill;                                                                                    ///< Fill flag to indicate whether it is the first fill or not.
 } FILL_CONDITION_STATUS_T;
 
 static DG_FILL_MODE_STATE_T fillState;                                                                       ///< Currently active fill state.
@@ -87,13 +88,13 @@
 static U32 concentrateTestStartTime;                                                                         ///< Starting time for concentrate test.
 static U32 concentratePumpPrimeCount;                                                                        ///< Interval count for concentrate pump prime.
 
-static F32 totalROFlowRateMLPM;                                                                           ///< Total RO flow rate over period of time.
+static F32 totalROFlowRateMLPM;                                                                              ///< Total RO flow rate over period of time.
 static F32 acidConductivityTotal;                                                                            ///< Total of acid conductivity during fill.
 static F32 dialysateConductivityTotal;                                                                       ///< Total of dialysate conductivity during fill.
 static U32 conductivitySampleCount;                                                                          ///< Sample count of conductivity during fill.
 
-static OVERRIDE_F32_T usedAcidVolumeML = { 0.0, 0.0, 0.0, 0.0 };                                            ///< The integrated acid concentration volume has been used in ml.
-static OVERRIDE_F32_T usedBicarbVolumeML = { 0.0, 0.0, 0.0, 0.0 };                                          ///< The integrated bicarb concentration volume has been used in ml.
+static OVERRIDE_F32_T usedAcidVolumeML = { 0.0, 0.0, 0.0, 0.0 };                                             ///< The integrated acid concentration volume has been used in ml.
+static OVERRIDE_F32_T usedBicarbVolumeML = { 0.0, 0.0, 0.0, 0.0 };                                           ///< The integrated bicarb concentration volume has been used in ml.
 
 // ********** private function prototypes **********
 
@@ -288,11 +289,25 @@
     // At the beginning the last and average temperatures are considered as the trimmer heater target temperature which
     // is the dialysate temperature
     fillStatus.fillTemperatureAverage    = getHeaterTargetTemperature( DG_TRIMMER_HEATER );
-    fillStatus.fillLastTemperature       = getHeaterTargetTemperature( DG_TRIMMER_HEATER );
+    fillStatus.fillLastTemperature       = getHeaterTargetTemperature( DG_TRIMMER_HEATER ) + RESERVOIR_EXTRA_TEMPERATURE;
+    fillStatus.isThisFirstFill           = TRUE;
 }
 
 /*********************************************************************//**
  * @brief
+ * The isThisTheFirstFill function returns the boolean flag that indicates
+ * whether this is the first fill of a treatment or not.
+ * @details Inputs: none
+ * @details Outputs: none
+ * @return fillStatus.isThisFirstFill
+ *************************************************************************/
+BOOL isThisTheFirstFill( void )
+{
+    return fillStatus.isThisFirstFill;
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleCheckInletWaterState function checks for inlet water quality
  * before jumping to dialysate production state.
  * @details Inputs: Temperature and conductivity alarms
@@ -309,9 +324,10 @@
     {
         concentrateTestStartTime = getMSTimerCount();
 #ifndef DISABLE_MIXING
-        setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP2_BICARB, CONCENTRATE_PUMP_MAX_SPEED );
-        requestConcentratePumpOff( CONCENTRATEPUMPS_CP1_ACID );
-        requestConcentratePumpOn( CONCENTRATEPUMPS_CP2_BICARB );
+
+            setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP2_BICARB, CONCENTRATE_PUMP_MAX_SPEED );
+            requestConcentratePumpOff( CONCENTRATEPUMPS_CP1_ACID );
+            requestConcentratePumpOn( CONCENTRATEPUMPS_CP2_BICARB );
 #endif
         result = DG_FILL_MODE_STATE_BICARB_PUMP_CHECK;
     }
@@ -587,6 +603,7 @@
         fillStatus.fillTemperatureRunningSum = 0.0;
         fillStatus.fillSampleCounter         = 1;
         fillStatus.fillLastTemperature       = getTemperatureValue( (U32)TEMPSENSORS_OUTLET_PRIMARY_HEATER );
+        fillStatus.isThisFirstFill           = FALSE;
 
         // Write the latest fill data into the RTC RAM for heaters control
         // TODO test this and make sure it is writing it correctly