Index: firmware/App/Modes/FPModes/ModeGenPermeate.c
===================================================================
diff -u -r9b06dafd96aca26795e2aeb05c21a5824b3db97a -r846073b88a25474464d43b4c0e8f300b52021f96
--- firmware/App/Modes/FPModes/ModeGenPermeate.c	(.../ModeGenPermeate.c)	(revision 9b06dafd96aca26795e2aeb05c21a5824b3db97a)
+++ firmware/App/Modes/FPModes/ModeGenPermeate.c	(.../ModeGenPermeate.c)	(revision 846073b88a25474464d43b4c0e8f300b52021f96)
@@ -29,6 +29,7 @@
 #include "PIControllers.h"
 #include "ROPump.h"
 #include "TaskGeneral.h"
+#include "TDInterface.h"
 #include "Timers.h"
 #include "Valves.h"
 #include "WaterQualityMonitor.h"
@@ -46,6 +47,7 @@
 #define PUMP_REST_TIMEOUT_MS                         ( 3 * MS_PER_SECOND )                        ///< Duraion for open loop control at the start of tank fill/full state ( in ms )
 #define RO_REJECTION_WAIT_TIME_MS                    ( 8 * MS_PER_SECOND )                        ///< RO rejection alarm wait time. 5 seconds for RR to stabilize and 3 seconds for calculating rolling average ( in ms )
 #define MIN_SAMPLES_NEEDED_FOR_DUTY_CYCLE_AVG        10                                           ///< Minimum number for samples needed for calculating the average duty cycle
+#define MIN_RO_PUMP_DUTY_CYCLE                       0.5                                          ///< Minimum RO pump duty cycle to start in fill/full state
 #define PERMEATE_FLOW_OUT_OF_RANGE_TIMEOUT_MS        ( 12 * MS_PER_SECOND )                       ///< Permeate flow low tolerance out of range timeout
 #define PERMEATE_TANK_EMPTY_LEVEL_VOL_ML             0                                            ///< Permeate tank volume in empty level ( in ml )
 #define PERMEATE_TANK_LOW_LEVEL_VOL_ML               957                                          ///< Permeate tank volume in low level ( in ml )
@@ -248,14 +250,11 @@
  *************************************************************************/
 static F32 getTankFullAlarmTimeout( void )
 {
-    F32 expectedDeprimeTime = 0.0F;
-    F32 expectedTankFullTime = 0.0F;
-    F32 ddConsumptionRate = getTDDialysateFlowrate() + RINSE_PUMP_TARGET_FLOW;
+    F32 ddConsumptionRate    = getTDDialysateFlowrate() + RINSE_PUMP_TARGET_FLOW;
+    F32 expectedTankFullTime = ( ( PERMEATE_TANK_HIGH_LEVEL_VOL_ML - PERMEATE_TANK_LOW_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
+    F32 expectedDeprimeTime  = ( ( PERMEATE_TANK_LOW_LEVEL_VOL_ML - PERMEATE_TANK_EMPTY_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
+    tankFullAlarmTimeout     = expectedTankFullTime + expectedDeprimeTime;
 
-    expectedTankFullTime = ( ( PERMEATE_TANK_HIGH_LEVEL_VOL_ML - PERMEATE_TANK_LOW_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
-    expectedDeprimeTime  = ( ( PERMEATE_TANK_LOW_LEVEL_VOL_ML - PERMEATE_TANK_EMPTY_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
-    tankFullAlarmTimeout = expectedTankFullTime + expectedDeprimeTime;
-
     return tankFullAlarmTimeout;
 }
 
@@ -268,14 +267,11 @@
  *************************************************************************/
 static F32 getTankFillAlarmTimeout( void )
 {
-    F32 expectedOverfillTime = 0.0F;
-    F32 expectedTankFillTime = 0.0F;
-    F32 ddConsumptionRate = getTDDialysateFlowrate() + RINSE_PUMP_TARGET_FLOW;
+    F32 ddConsumptionRate    = getTDDialysateFlowrate() + RINSE_PUMP_TARGET_FLOW;
+    F32 expectedTankFillTime = ( ( PERMEATE_TANK_HIGH_LEVEL_VOL_ML - PERMEATE_TANK_LOW_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
+    F32 expectedOverfillTime = ( ( PERMEATE_TANK_FULL_LEVEL_VOL_ML - PERMEATE_TANK_HIGH_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
+    tankFillAlarmTimeout     = ( expectedTankFillTime + ( expectedOverfillTime / 2 ) );
 
-    expectedTankFillTime = ( ( PERMEATE_TANK_HIGH_LEVEL_VOL_ML - PERMEATE_TANK_LOW_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
-    expectedOverfillTime  = ( ( PERMEATE_TANK_FULL_LEVEL_VOL_ML - PERMEATE_TANK_HIGH_LEVEL_VOL_ML ) / ddConsumptionRate ) * SEC_PER_MIN;
-    tankFillAlarmTimeout = ( expectedTankFillTime + ( expectedOverfillTime / 2 ) );
-
     return tankFillAlarmTimeout;
 }
 
@@ -297,6 +293,8 @@
     {
         case FP_GENP_TANK_FILL_STATE:
             initDutyCycle = isFillAvgValid ? prevFillAvgDutyCycle : getCurrentROPumpDutyCyclePCT();
+            // set the duty cycle to minimum of 0.5 if the value is zero
+            initDutyCycle = initDutyCycle == 0.0F ? MIN_RO_PUMP_DUTY_CYCLE : initDutyCycle;
             setROPumpTargetDutyCycle( initDutyCycle, TRUE );
             timeInState = getMSTimerCount();
             tankFillAlarmTimer = getMSTimerCount();
@@ -308,6 +306,8 @@
 
         case FP_GENP_TANK_FULL_STATE:
             initDutyCycle = isFullAvgValid ? prevFullAvgDutyCycle : getCurrentROPumpDutyCyclePCT();
+            // set the duty cycle to minimum of 0.5 if the value is zero
+            initDutyCycle = initDutyCycle == 0.0F ? MIN_RO_PUMP_DUTY_CYCLE : initDutyCycle;
             setROPumpTargetDutyCycle( initDutyCycle, TRUE );
             timeInState = getMSTimerCount();
             tankFullAlarmTimer = getMSTimerCount();