Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -ree53e23ebcd35a6ef258ecf2f24a47dd47be71b0 -rf90e1ab6241f06d7439e3b7b6060862c7e20042d
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision ee53e23ebcd35a6ef258ecf2f24a47dd47be71b0)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision f90e1ab6241f06d7439e3b7b6060862c7e20042d)
@@ -637,7 +637,7 @@
 static HD_PRE_TREATMENT_PRIME_STATE_T handlePrimeDialysateBypassState( void )
 {
     HD_PRE_TREATMENT_PRIME_STATE_T state = HD_PRIME_DIALYSATE_BYPASS_STATE;
-    F32 const loadcellWeight = getLoadCellWeight( LOAD_CELL_RESERVOIR_2_PRIMARY );
+    F32 const loadcellWeight = getLoadCellWeight( LOAD_CELL_RESERVOIR_1_PRIMARY );
     F32 const weightChange = fabs( 1.0 - ( previousLoadCellReading / loadcellWeight ) );
 
     if ( weightChange < LOAD_CELL_VOLUME_NOISE_TOLERANCE )
@@ -735,7 +735,7 @@
 {
     HD_PRE_TREATMENT_PRIME_STATE_T state = HD_PRIME_DIALYSATE_DIALYZER_STATE;
 
-    F32 const loadcellWeight = getLoadCellWeight( LOAD_CELL_RESERVOIR_1_PRIMARY );
+    F32 const loadcellWeight = getLoadCellWeight( LOAD_CELL_RESERVOIR_2_PRIMARY );
 
     F32 const weightChange = fabs( 1.0 - ( previousLoadCellReading / loadcellWeight ) );