Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -r16cd633e1d18224face6f977120ccab3846e7671 -r945dcc1391faefe5f4ddb4f505361501d008e293
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 16cd633e1d18224face6f977120ccab3846e7671)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 945dcc1391faefe5f4ddb4f505361501d008e293)
@@ -202,7 +202,7 @@
 static DG_FILL_MODE_STATE_T handleDeliverDialysateState( void )
 {
     DG_FILL_MODE_STATE_T result = DG_FILL_MODE_STATE_DELIVER_DIALYSATE;
-    LOAD_CELL_ID_T fillWeightLoadCell = LOAD_CELL_A1;
+    RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();
 
     handleDialysateMixing();
     checkConcentrateConductivity();
@@ -220,14 +220,8 @@
         result = DG_FILL_MODE_STATE_DIALYSATE_PRODUCTION;
     }
 
-    // determine which load cell to use for fill volume - we want weight of inactive reservoir
-    if ( RESERVOIR_1 == getActiveReservoir() )
-    {
-        fillWeightLoadCell = LOAD_CELL_B1;
-    }
-
     // if we've reached our target fill to volume (by weight), we're done filling - go back to re-circ mode
-    if ( getReservoirFillVolumeTargetMl() <= getLoadCellFilteredWeight( fillWeightLoadCell ) )
+    if ( hasTargetFillVolumeReached( inactiveReservoir ) )
     {
         requestConcentratePumpOff();
         requestNewOperationMode( DG_MODE_CIRC );