Index: firmware/App/Controllers/Valves.c
===================================================================
diff -u -r8ed20540782ec6b81fc870c33c7a7e6f589a6ff3 -r4d635c390c184a405bdc96e56ce35505fe3868c5
--- firmware/App/Controllers/Valves.c	(.../Valves.c)	(revision 8ed20540782ec6b81fc870c33c7a7e6f589a6ff3)
+++ firmware/App/Controllers/Valves.c	(.../Valves.c)	(revision 4d635c390c184a405bdc96e56ce35505fe3868c5)
@@ -302,15 +302,17 @@
  * @details Inputs: valvesStatus
  * @details Outputs: valvesStatus
  * @param valve that is set to be homed
+ * @param force flag indicating whether homing should be forced even if already homed
+ * @param cartridge flag indicating whether a cartridge may be present requiring a more lax homing
  * @return TRUE if the homing command accepted otherwise, FALSE
  *************************************************************************/
-BOOL homeValve( VALVE_T valve )
+BOOL homeValve( VALVE_T valve, BOOL force, BOOL cartridge )
 {
     BOOL result = FALSE;
 
     if ( valve < NUM_OF_VALVES )
     {   // If haven't already homed the valves, home the valves
-        if ( valvesStatus[ valve ].hasValveBeenHomed != TRUE )
+        if ( ( valvesStatus[ valve ].hasValveBeenHomed != TRUE ) || ( VALVE_FORCE_HOME == force ) )
         {
             valvesStatus[ valve ].hasHomingBeenRequested = TRUE;
         }
Index: firmware/App/Controllers/Valves.h
===================================================================
diff -u -r19f13e67288117e7f81c1245a75cc6b5f8aaf899 -r4d635c390c184a405bdc96e56ce35505fe3868c5
--- firmware/App/Controllers/Valves.h	(.../Valves.h)	(revision 19f13e67288117e7f81c1245a75cc6b5f8aaf899)
+++ firmware/App/Controllers/Valves.h	(.../Valves.h)	(revision 4d635c390c184a405bdc96e56ce35505fe3868c5)
@@ -53,6 +53,11 @@
     NUM_OF_VALVES                       ///< Number of valves
 } VALVE_T;
 
+#define VALVE_NO_FORCE_HOME             FALSE       ///< Do not re-home valve if already homed - just go to position A instead
+#define VALVE_FORCE_HOME                TRUE        ///< Force valve to home even if already homed
+#define VALVE_NO_CARTRIDGE_PRESENT      FALSE       ///< No cartridge should be present, so insist homed positions to be near where expected
+#define VALVE_CARTRIDGE_MAY_BE_PRESENT  TRUE        ///< A cartridge may be present, so allow for homed positions to be further away from where expected
+
 #pragma pack(push, 1)
 /// HD valves broadcast data
 typedef struct
@@ -90,7 +95,7 @@
 
 void execValves( void );
 
-BOOL homeValve( VALVE_T valve );
+BOOL homeValve( VALVE_T valve, BOOL force, BOOL cartridge );
 
 BOOL setValvePosition( VALVE_T valve, VALVE_POSITION_T position );
 
Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -rc1b9ac0dbf2196280895d2e440dd7ac288ac8424 -r4d635c390c184a405bdc96e56ce35505fe3868c5
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision c1b9ac0dbf2196280895d2e440dd7ac288ac8424)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 4d635c390c184a405bdc96e56ce35505fe3868c5)
@@ -669,7 +669,7 @@
             // Home pumps and valves
             for ( valve = VDI; valve < NUM_OF_VALVES; ++valve )
             {
-                homeValve( valve );
+                homeValve( valve, VALVE_NO_FORCE_HOME, VALVE_CARTRIDGE_MAY_BE_PRESENT );
             }
             homeBloodPump();
             homeDialInPump();
Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -rc1b9ac0dbf2196280895d2e440dd7ac288ac8424 -r4d635c390c184a405bdc96e56ce35505fe3868c5
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision c1b9ac0dbf2196280895d2e440dd7ac288ac8424)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision 4d635c390c184a405bdc96e56ce35505fe3868c5)
@@ -447,7 +447,7 @@
     setValvePosition( VDI, VALVE_POSITION_C_CLOSE );
     setValvePosition( VDO, VALVE_POSITION_C_CLOSE );
     setValvePosition( VBA, VALVE_POSITION_C_CLOSE );
-    setValvePosition( VBV, VALVE_POSITION_C_CLOSE );
+    setValvePosition( VBV, VALVE_POSITION_B_OPEN );  // Allow fluid to get to VBA per DEN-14171
     setValveAirTrap( STATE_OPEN );
 
     signalDialOutPumpHardStop();
Index: firmware/App/Modes/SelfTests.c
===================================================================
diff -u -rc1b9ac0dbf2196280895d2e440dd7ac288ac8424 -r4d635c390c184a405bdc96e56ce35505fe3868c5
--- firmware/App/Modes/SelfTests.c	(.../SelfTests.c)	(revision c1b9ac0dbf2196280895d2e440dd7ac288ac8424)
+++ firmware/App/Modes/SelfTests.c	(.../SelfTests.c)	(revision 4d635c390c184a405bdc96e56ce35505fe3868c5)
@@ -754,7 +754,7 @@
 
     for ( valve = VDI; valve < NUM_OF_VALVES; ++valve )
     {
-        homeValve( valve );
+        homeValve( valve, VALVE_FORCE_HOME, VALVE_NO_CARTRIDGE_PRESENT );
     }
 
     if ( TRUE == doesAlarmStatusIndicateStop() )
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -rc1b9ac0dbf2196280895d2e440dd7ac288ac8424 -r4d635c390c184a405bdc96e56ce35505fe3868c5
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision c1b9ac0dbf2196280895d2e440dd7ac288ac8424)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 4d635c390c184a405bdc96e56ce35505fe3868c5)
@@ -4820,7 +4820,7 @@
         U32 valve;
 
         memcpy( &valve, message->payload, sizeof(U32) );
-        homeValve( (VALVE_T)valve );
+        homeValve( (VALVE_T)valve, VALVE_FORCE_HOME, VALVE_NO_CARTRIDGE_PRESENT );
 
         result = TRUE;
     }