Index: firmware/App/Modes/ModeTreatmentParams.c
===================================================================
diff -u -r76daf406b551ad71a8ba5417254a31c563564038 -rfd6b0b8b940da4eff0bf96e927af670f15b7bc0f
--- firmware/App/Modes/ModeTreatmentParams.c	(.../ModeTreatmentParams.c)	(revision 76daf406b551ad71a8ba5417254a31c563564038)
+++ firmware/App/Modes/ModeTreatmentParams.c	(.../ModeTreatmentParams.c)	(revision fd6b0b8b940da4eff0bf96e927af670f15b7bc0f)
@@ -689,13 +689,13 @@
             case TREATMENT_PARAM_HEPARIN_DISPENSE_RATE:
                 result  = ( ( value.sFlt >= hdInstitutionalRecord.minHeparinDispRateMLPHR ) &&
                             ( value.sFlt <= hdInstitutionalRecord.maxHeparinDispRateMLPHR ) ? TRUE : FALSE );
-                result |= ( value.sFlt <= NEARLY_ZERO ? TRUE : FALSE ); // Even if the minimum is not 0, 0 is accepted meaning heparin can be turned off
+                result |= ( fabs( value.sFlt ) <= NEARLY_ZERO ? TRUE : FALSE ); // Even if the minimum is not 0, 0 is accepted meaning heparin can be turned off
                 break;
 
             case TREATMENT_PARAM_HEPARIN_BOLUS_VOLUME:
                 result  = ( ( value.sFlt >= hdInstitutionalRecord.minHeparinBolusVolumeML ) &&
                             ( value.sFlt <= hdInstitutionalRecord.maxHeparinBolusVolumeML ) ? TRUE : FALSE );
-                result |= ( value.sFlt <= NEARLY_ZERO ? TRUE : FALSE ); // Even if the minimum is not 0, 0 is accepted meaning heparin can be turned off
+                result |= ( fabs( value.sFlt ) <= NEARLY_ZERO ? TRUE : FALSE ); // Even if the minimum is not 0, 0 is accepted meaning heparin can be turned off
                 break;
 
             default: