Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -ra06e2c94a2c49609972b28f7ccd0647baabdb9b1 -rb3231e63a423fd2d8408c1859e2f58001266a5b5
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision a06e2c94a2c49609972b28f7ccd0647baabdb9b1)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision b3231e63a423fd2d8408c1859e2f58001266a5b5)
@@ -53,7 +53,8 @@
 #define CONCENTRATE_TEST_TIME_OUT_MS                    ( 30 * MS_PER_SECOND )                      ///< Concentrate test time out period in ms.
 #define WATER_QUALITY_CHECK_TIME_OUT_MS                 ( 30 * MS_PER_SECOND )                      ///< Inlet water quality check time out period in ms.
 
-#define CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS        ( 5 * MS_PER_SECOND )                       ///< Persistence period for conductivity error.
+#define CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS        ( 15 * MS_PER_SECOND )                      ///< Persistence period for conductivity error.
+#define CONDUCTIVITY_CLEAR_PERSISTENCE_PERIOD_MS        ( 5 * MS_PER_SECOND )                       ///< Persistence period for conductivity error.
 
 #define DIALYSATE_TEMPERATURE_TOLERANCE_C               2.0                                         ///< Dialysate temperature tolerance in degree C.
 
@@ -104,8 +105,7 @@
     dialysateConductivityTotal = 0.0;
     dialysateConductivitySampleCount = 0;
 
-    initPersistentAlarm( ALARM_ID_ACID_CONDUCTIVITY_OUT_OF_RANGE, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS );
-    initPersistentAlarm( ALARM_ID_DIALYSATE_CONDUCTIVITY_OUT_OF_RANGE, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS );
+    initPersistentAlarm( ALARM_ID_DIALYSATE_CONDUCTIVITY_OUT_OF_RANGE, CONDUCTIVITY_CLEAR_PERSISTENCE_PERIOD_MS, CONDUCTIVITY_ERROR_PERSISTENCE_PERIOD_MS );
 }
 
 /*********************************************************************//**
@@ -315,6 +315,8 @@
 
 #ifndef DISABLE_DIALYSATE_CHECK
     if ( TRUE == isBicarbConductivityInRange() )
+#else
+    if ( TRUE )
 #endif
     {
         concentrateTestStartTime = getMSTimerCount();
@@ -348,6 +350,8 @@
 
 #ifndef DISABLE_DIALYSATE_CHECK
     if ( TRUE == isAcidConductivityInRange() )
+#else
+    if ( TRUE )
 #endif
     {
         requestConcentratePumpsOn( CONCENTRATEPUMPS_CP1_ACID );
@@ -392,6 +396,10 @@
              ( TRUE == isAlarmActive( ALARM_ID_DIALYSATE_CONDUCTIVITY_OUT_OF_RANGE ) ) )
         {
             result = DG_FILL_MODE_STATE_PAUSED;
+            requestConcentratePumpsOff( CONCENTRATEPUMPS_CP1_ACID );
+            requestConcentratePumpsOff( CONCENTRATEPUMPS_CP2_BICARB );
+            signalROPumpHardStop();
+            stopPrimaryHeater();
         }
     }
 
@@ -416,6 +424,8 @@
              ( isAlarmActive( ALARM_ID_DIALYSATE_CONDUCTIVITY_OUT_OF_RANGE ) ) != TRUE )
         {
             result = DG_FILL_MODE_STATE_CHECK_INLET_WATER;
+            setROPumpTargetFlowRate( TARGET_RO_FLOW_RATE_L, TARGET_RO_PRESSURE_PSI );
+            startPrimaryHeater();
         }
     }
 
@@ -433,10 +443,12 @@
 static DG_FILL_MODE_STATE_T handleDeliverDialysateState( void )
 {
     F32 avgDialysateConductivity;
+    F32 integratedVolume_mL;
     DG_FILL_MODE_STATE_T result = DG_FILL_MODE_STATE_DELIVER_DIALYSATE;
     DG_RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();
 
     totalROFlowRate_LPM += getMeasuredROFlowRate();
+    integratedVolume_mL = totalROFlowRate_LPM * RO_FLOW_INTEGRATOR * ACID_BICARB_CONCENTRATE_ADDITION_MULTIPLER;
     dialysateConductivityTotal += getConductivityValue( CONDUCTIVITYSENSORS_CD2_SENSOR );
     dialysateConductivitySampleCount++;
 
@@ -464,10 +476,9 @@
     }
 
     // if we've reached our target fill to volume (by weight), we're done filling - go back to re-circ mode
-    if ( TRUE == hasTargetFillVolumeBeenReached( inactiveReservoir ) )
+    if ( ( TRUE == hasTargetFillVolumeBeenReached( inactiveReservoir ) ) || ( ( integratedVolume_mL - reservoirBaseWeight ) >= MAX_RESERVOIR_VOLUME_ML ) )
     {
         F32 const filledVolume_mL = getReservoirWeight( inactiveReservoir ) - reservoirBaseWeight;
-        F32 const integratedVolume_mL = totalROFlowRate_LPM * RO_FLOW_INTEGRATOR * ACID_BICARB_CONCENTRATE_ADDITION_MULTIPLER;
         F32 const integratedVolumeToLoadCellReadingPercent = fabs( 1 - ( filledVolume_mL / integratedVolume_mL ) );
 
         if ( integratedVolumeToLoadCellReadingPercent > FLOW_INTEGRATED_VOLUME_CHECK_TOLERANCE )
Index: firmware/App/Services/Reservoirs.c
===================================================================
diff -u -rebbb1f85550a1f9b8f946655f7b2b63f76fbf67d -rb3231e63a423fd2d8408c1859e2f58001266a5b5
--- firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision ebbb1f85550a1f9b8f946655f7b2b63f76fbf67d)
+++ firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision b3231e63a423fd2d8408c1859e2f58001266a5b5)
@@ -34,7 +34,6 @@
 // ********** private definitions **********
 
 #define MIN_RESERVOIR_VOLUME_ML         0                                               ///< Minimum reservoir volume in mL.
-#define MAX_RESERVOIR_VOLUME_ML         2000                                            ///< Maximum reservoir volume in mL.
 #define DEFAULT_FILL_VOLUME_ML          1700                                            ///< Default fill volume for treatment in mL.
 #define DISINFECT_FILL_VOLUME_ML        2400                                            ///< Fill volume for disinfection in mL.
 #define MAX_FILL_VOLUME_ML              MAX_RESERVOIR_VOLUME_ML                         ///< Maximum fill volume in mL.
Index: firmware/App/Services/Reservoirs.h
===================================================================
diff -u -rebbb1f85550a1f9b8f946655f7b2b63f76fbf67d -rb3231e63a423fd2d8408c1859e2f58001266a5b5
--- firmware/App/Services/Reservoirs.h	(.../Reservoirs.h)	(revision ebbb1f85550a1f9b8f946655f7b2b63f76fbf67d)
+++ firmware/App/Services/Reservoirs.h	(.../Reservoirs.h)	(revision b3231e63a423fd2d8408c1859e2f58001266a5b5)
@@ -31,6 +31,8 @@
 
 // ********** public definitions **********
 
+#define MAX_RESERVOIR_VOLUME_ML         2000            ///< Maximum reservoir volume in mL.
+
 #pragma pack(push,1)
 
 /// Fill command data structure.