Index: firmware/App/Modes/ModeTreatmentParams.c
===================================================================
diff -u -rad4a8d997ddd84013b4a67904a6ecfada5834801 -r0aba18162f271555453e7f9266f990a7c22779a6
--- firmware/App/Modes/ModeTreatmentParams.c	(.../ModeTreatmentParams.c)	(revision ad4a8d997ddd84013b4a67904a6ecfada5834801)
+++ firmware/App/Modes/ModeTreatmentParams.c	(.../ModeTreatmentParams.c)	(revision 0aba18162f271555453e7f9266f990a7c22779a6)
@@ -642,9 +642,8 @@
                 break;
 
             case TREATMENT_PARAM_HEPARIN_PRE_STOP_TIME:
-                result  = ( ( value.uInt >= hdInstitutionalRecord.minStopHeparinDispBeforeTxEndMIN ) &&
-                            ( value.uInt <= hdInstitutionalRecord.maxStopHeparinDispBeforeTxEndMIN ) ? TRUE : FALSE );
-                result |= ( 0 == value.uInt ? TRUE : FALSE ); // Even if the minimum is not 0, 0 is accepted meaning heparin can be turned off
+                result = ( ( value.uInt >= hdInstitutionalRecord.minStopHeparinDispBeforeTxEndMIN ) &&
+                           ( value.uInt <= hdInstitutionalRecord.maxStopHeparinDispBeforeTxEndMIN ) ? TRUE : FALSE );
                 break;
 
             case TREATMENT_PARAM_SALINE_BOLUS_VOLUME:
@@ -1005,12 +1004,15 @@
     result           = isTreatmentParamInRange( param, integerData );
 
     // Validate parameter
-    if ( ( param <= TREATMENT_PARAM_LAST_UINT ) && ( TRUE == result ) )
+    if ( param <= TREATMENT_PARAM_LAST_UINT )
     {
-        CRITICAL_DATAS_T data = treatmentParameters[ param ].data;
+        if ( TRUE == result )
+        {
+            CRITICAL_DATAS_T data = treatmentParameters[ param ].data;
 
-        data.uInt = value;
-        result = setCriticalData( &treatmentParameters[ param ], data );
+            data.uInt = value;
+            result = setCriticalData( &treatmentParameters[ param ], data );
+        }
     }
     else
     {
@@ -1039,12 +1041,15 @@
     result               = isTreatmentParamInRange( param, unsignedIntData );
 
     // Validate parameter
-    if ( ( param >= TREATMENT_PARAM_FIRST_INT ) && ( param <= TREATMENT_PARAM_LAST_INT ) && ( TRUE == result ) )
+    if ( ( param >= TREATMENT_PARAM_FIRST_INT ) && ( param <= TREATMENT_PARAM_LAST_INT ) )
     {
-        CRITICAL_DATAS_T data = treatmentParameters[ param ].data;
+        if ( TRUE == result )
+        {
+            CRITICAL_DATAS_T data = treatmentParameters[ param ].data;
 
-        data.sInt = value;
-        result = setCriticalData( &treatmentParameters[ param ], data );
+            data.sInt = value;
+            result = setCriticalData( &treatmentParameters[ param ], data );
+        }
     }
     else
     {
@@ -1073,12 +1078,15 @@
     result         = isTreatmentParamInRange( param, floatData );
 
     // Validate parameter
-    if ( ( param >= TREATMENT_PARAM_FIRST_F32 ) && ( param < NUM_OF_TREATMENT_PARAMS ) && ( TRUE == result ) )
+    if ( ( param >= TREATMENT_PARAM_FIRST_F32 ) && ( param < NUM_OF_TREATMENT_PARAMS ) )
     {
-        CRITICAL_DATAS_T data = treatmentParameters[ param ].data;
+        if ( TRUE == result )
+        {
+            CRITICAL_DATAS_T data = treatmentParameters[ param ].data;
 
-        data.sFlt = value;
-        result = setCriticalData( &treatmentParameters[ param ], data );
+            data.sFlt = value;
+            result = setCriticalData( &treatmentParameters[ param ], data );
+        }
     }
     else
     {