Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -r7f64bdbf118609be8afc6fc7a3bd0ffe0cc2791a -r2de5552645e060e73d186ffb5a20223f163d4673
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 7f64bdbf118609be8afc6fc7a3bd0ffe0cc2791a)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 2de5552645e060e73d186ffb5a20223f163d4673)
@@ -63,8 +63,8 @@
 
 #define CONC_PUMPS_PRIME_AT_MAX_SPEED_TIME_OUT_MS       ( 7 * MS_PER_SECOND )                                ///< Concentrate pumps prime at maximum speed timeout in milliseconds.
 #define CONC_PUMPS_PRIME_CHECK_COND_SNSRS_TIME_OUT_MS   ( 10 * MS_PER_SECOND )                               ///< Concentrate pumps prime check conductivity sensors timeout in milliseconds.
-#define CONC_PUMPS_PRIME_MAX_ALLOWED_PRIME_TIME_OUT_MS  ( 25 * MS_PER_SECOND )                               ///< Concentrate pumps prime maximum allowed timeout in prime in milliseconds.
-
+#define CONC_PUMPS_PRIME_MAX_ALLOWED_PRIME_TIME_OUT_MS  ( 50 * MS_PER_SECOND )                               ///< Concentrate pumps prime maximum allowed timeout in prime in milliseconds.
+#define NINTY_FIVE_PERCENT_FACTOR                       0.95F                                                ///< Ninety five percent of expected conductivity
 #define FLOW_INTEGRATED_VOLUME_CHECK_TOLERANCE          0.1F                                                 ///< Flow integrated volume has 10% tolerance compare to load cell reading.
 
 #define FIVE_PERCENT_FACTOR                             0.05F                                                ///< 5.0 / 100.0  used to calculate conductivity within range of -/+ 5%.
@@ -789,15 +789,15 @@
         if ( TRUE == didTimeout( concPumpPrimeStartTimeMS, CONC_PUMPS_PRIME_CHECK_COND_SNSRS_TIME_OUT_MS ) )
         {
             /* Once the time for priming the concentrate lines has elapsed, check the mixing conductivity of the sensors
-             * If the acid and bicarb conductivity values are at about 50% of the target concentrate during fill, transition to the next state
-             * If the acid and bicarb conductivity values are not at 50% but the maximum prime time has elapsed, transition to the next state
+             * If the acid and bicarb conductivity values are at about 95% of the target concentrate during fill, transition to the next state
+             * If the acid and bicarb conductivity values are not at 95% but the maximum prime time has elapsed, transition to the next state
              */
             F32 acidConduSPerCM       = getConductivityValue( CONDUCTIVITYSENSORS_CD1_SENSOR );
             F32 bicarbConduSPerCM     = getConductivityValue( CONDUCTIVITYSENSORS_CD2_SENSOR );
             F32 acidFillConduSPerCM   = chemicalsCond.fillCondValues[ chemicalsTypes.acidType ][ FILL_COND_NORMAL_OP ].acidConduSPerCM;
             F32 bicarbFillConduSPerCM = chemicalsCond.fillCondValues[ chemicalsTypes.acidType ][ FILL_COND_NORMAL_OP ].bicarbConduSPerCM;
 
-            if ( ( acidConduSPerCM >= ( acidFillConduSPerCM * HALF ) ) && ( bicarbConduSPerCM >= ( bicarbFillConduSPerCM * HALF ) ) )
+            if ( ( acidConduSPerCM >= ( acidFillConduSPerCM * NINTY_FIVE_PERCENT_FACTOR ) ) && ( bicarbConduSPerCM >= ( bicarbFillConduSPerCM * NINTY_FIVE_PERCENT_FACTOR ) ) )
             {
                 result = DG_FILL_MODE_STATE_DELIVER_DIALYSATE;
                 setModeFillStateTransition( result );