Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r7aa0c684cca238a9697867ff72e5c3f5f2edb379 -r323024b3c7b988f4da87d3e5ef54f395db1142f8
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 7aa0c684cca238a9697867ff72e5c3f5f2edb379)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 323024b3c7b988f4da87d3e5ef54f395db1142f8)
@@ -722,12 +722,12 @@
             if ( D5_HEAT == heater )
             {
                 alarm       = ALARM_ID_DD_FLUID_TOO_LOW_WHILE_D5_HEAT_IS_ON;
-                isLevelLow  = ( ( getFloaterStatus( D6_LEVL ) != 0 )? FALSE : TRUE );
+                isLevelLow  = ( ( getFloaterStatus( D6_LEVL ) != LVL_STATE_EMPTY )? FALSE : TRUE );
             }
             else
             {
                 alarm       = ALARM_ID_DD_FLUID_TOO_LOW_WHILE_D45_HEAT_IS_ON;
-                isLevelLow  = ( ( getLevelStatus( D46_LEVL ) != 0 )? FALSE : TRUE );
+                isLevelLow  = ( ( getLevelStatus( D46_LEVL ) != LEVEL_STATE_LOW )? FALSE : TRUE );
             }
 
             checkPersistentAlarm( alarm, isLevelLow, 0.0F, 0.0F );