Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -rd6a491cb0614634342be3ea058d51a68ef0c788c -ra73cb04b05c061e2c9c7264869296b520ccbfc8a
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision d6a491cb0614634342be3ea058d51a68ef0c788c)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision a73cb04b05c061e2c9c7264869296b520ccbfc8a)
@@ -679,7 +679,7 @@
     patientConnectionConfirm = FALSE;
     treatmentStartRequested = FALSE;
 
-    doorClosedRequired( TRUE, TRUE );
+    doorClosedRequired( FALSE, TRUE );
 
     for ( valve = VDI; valve < NUM_OF_VALVES; ++valve )
     {
@@ -1022,11 +1022,13 @@
 {
     HD_PRE_TREATMENT_PAT_CONN_STATE_T nextState = PRE_TREATMENT_PAT_CONN_WAIT_FOR_UF_VOL_STATE;
 
+    // Look for cartridge door to open and then close (indicating user inverted dialyzer)
+    handlePatientConnectionDoorOpened();
+
     // If UF volume set by user, move on to next state
     if ( TRUE == setUFVolStatus )
     {
         setUFVolStatus = FALSE;
-        doorClosedRequired( FALSE, TRUE );
         nextState = PRE_TREATMENT_PAT_CONN_WAIT_FOR_DLZR_INVERT_STATE;
     }