Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -rbaaf3dc55c2dee07d04efb97022fd2329a5bd73d -r4b4eab2b311a43bd1fa35f24e427a8beb17df8b0
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision baaf3dc55c2dee07d04efb97022fd2329a5bd73d)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 4b4eab2b311a43bd1fa35f24e427a8beb17df8b0)
@@ -355,7 +355,7 @@
                 alarm     = ALARM_ID_DIALYSATE_FLOW_TOO_LOW_WHILE_TRIMMER_HEATER_IS_ON;
                 measFlow  = getMeasuredRawFlowRateLPM( DIALYSATE_FLOW_SENSOR );
                 minFlow   = MIN_DIALYSATE_FLOWRATE_LPM;
-                isFlowLow = ( measFlow - minFlow < NEARLY_ZERO ? TRUE : FALSE );
+                isFlowLow = ( measFlow > minFlow ? FALSE : TRUE );
             }
 
             checkPersistentAlarm( alarm, isFlowLow, measFlow, minFlow );