Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -r353d01d31bc69d4d1901ff09097ee610bb1c9dbc -ra3960210792d0811093a6913e505d43eda1918ea
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 353d01d31bc69d4d1901ff09097ee610bb1c9dbc)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision a3960210792d0811093a6913e505d43eda1918ea)
@@ -119,15 +119,16 @@
  *************************************************************************/
 void initFillMode( void )
 {
-    fillState                            = DG_FILL_MODE_STATE_START;
-    dialysateFillStartTime               = 0;
-    reservoirBaseWeight                  = 0.0;
-    totalROFlowRate_mL_min               = 0.0;
-    concentrateTestStartTime             = 0;
-    acidConductivityTotal                = 0.0;
-    dialysateConductivityTotal           = 0.0;
-    conductivitySampleCount              = 0;
-    concentratePumpPrimeCount            = 0;
+    fillState                  = DG_FILL_MODE_STATE_START;
+    dialysateFillStartTime     = 0;
+    reservoirBaseWeight        = 0.0;
+    totalROFlowRate_mL_min     = 0.0;
+    concentrateTestStartTime   = 0;
+    acidConductivityTotal      = 0.0;
+    dialysateConductivityTotal = 0.0;
+    conductivitySampleCount    = 0;
+    concentratePumpPrimeCount  = 0;
+
     // Get the heaters info form the NV data management
     DG_HEATERS_RECORD_T heaterInfo       = getHeatersInfoReocrd();
     // If the data in the NV data management was not initialized properly, set it to 0 otherwise, set the average flow rate
@@ -136,6 +137,9 @@
     fillStatus.fillSampleCounter         = 0;
     fillStatus.fillTemperatureRunningSum = 0.0;
     fillStatus.fillTemperatureAverage    = 0.0;
+    // The last fill temperature is initialized to TPo because this value is used for heater calculations prior to filling the
+    // reservoirs. The first actual value will be updated at the end of the fill cycle.
+    fillStatus.fillLastTemperature       = getTemperatureValue( (U32)TEMPSENSORS_INLET_PRIMARY_HEATER );
 
     initPersistentAlarm( ALARM_ID_ACID_CONDUCTIVITY_OUT_OF_RANGE, 0, EMPTY_BOTTLE_DETECT_PERSISTENT_PERIOD_MS );
     initPersistentAlarm( ALARM_ID_BICARB_CONDUCTIVITY_OUT_OF_RANGE, 0, EMPTY_BOTTLE_DETECT_PERSISTENT_PERIOD_MS );
@@ -545,10 +549,10 @@
     // If we've reached our target fill to volume (by weight), we're done filling - go back to generation idle mode
     if ( TRUE == hasTargetFillVolumeBeenReached( inactiveReservoir ) )
     {
-        F32 const filledVolume_mL = getReservoirWeight( inactiveReservoir ) - reservoirBaseWeight;
-        F32 const integratedVolumeToLoadCellReadingPercent = fabs( 1 - ( filledVolume_mL / integratedVolume_mL ) );
-        F32 const avgAcidConductivity = acidConductivityTotal / conductivitySampleCount;  // TODO - should we be checking this below?
-        F32 const avgDialysateConductivity = dialysateConductivityTotal / conductivitySampleCount;
+        F32 filledVolume_mL = getReservoirWeight( inactiveReservoir ) - reservoirBaseWeight;
+        F32 integratedVolumeToLoadCellReadingPercent = fabs( 1 - ( filledVolume_mL / integratedVolume_mL ) );
+        F32 avgAcidConductivity = acidConductivityTotal / conductivitySampleCount;  // TODO - should we be checking this below?
+        F32 avgDialysateConductivity = dialysateConductivityTotal / conductivitySampleCount;
 
         if ( integratedVolumeToLoadCellReadingPercent > FLOW_INTEGRATED_VOLUME_CHECK_TOLERANCE )
         {