Index: firmware/App/Modes/ModeTreatmentParams.c
===================================================================
diff -u -rf760ffc4b10556e5186e9ceb90294262063440ca -rdab84d4ac15ba54bb02784c5e359cdc527e9ed05
--- firmware/App/Modes/ModeTreatmentParams.c	(.../ModeTreatmentParams.c)	(revision f760ffc4b10556e5186e9ceb90294262063440ca)
+++ firmware/App/Modes/ModeTreatmentParams.c	(.../ModeTreatmentParams.c)	(revision dab84d4ac15ba54bb02784c5e359cdc527e9ed05)
@@ -38,6 +38,8 @@
 
 #define MAX_DIALYSATE_VOLUME_ML                 ( 150 * ML_PER_LITER )  ///< Maximum dialysate volume (in mL)
 
+#define NO_HEPARIN_PRE_STOP_TIME_SET            0                       ///< Zero value indicates no Heparin pre-stop time was set by user
+
 /// Record for range and default of treatment parameters.
 typedef struct
 {
@@ -570,6 +572,15 @@
         result = FALSE;
     }
 
+    // Check Heparin pre-stop vs. no Heparin delivery
+    if ( ( stagedParams[ TREATMENT_PARAM_HEPARIN_PRE_STOP_TIME ].uInt > NO_HEPARIN_PRE_STOP_TIME_SET ) &&
+         ( stagedParams[ TREATMENT_PARAM_HEPARIN_DISPENSE_RATE ].sFlt < NEARLY_ZERO ) &&
+         ( stagedParams[ TREATMENT_PARAM_HEPARIN_BOLUS_VOLUME ].sFlt < NEARLY_ZERO ) )
+    {
+        reasons[ TREATMENT_PARAM_HEPARIN_PRE_STOP_TIME ] = REQUEST_REJECT_REASON_HEPARIN_PRESTOP_WITH_NO_DISPENSE;
+        result = FALSE;
+    }
+
     // Check arterial alarm limits dependency
     if ( arterialPresLimitDelta < MIN_PRESSURE_ALARM_LIMIT_DELTA_MMHG )
     {