Index: firmware/App/Modes/BloodPrime.c
===================================================================
diff -u -rf3d625e2593ced120c4a98b9ed7e28b132445642 -r931ca8779b64aa8bb68aa26d1f631d040a753007
--- firmware/App/Modes/BloodPrime.c	(.../BloodPrime.c)	(revision f3d625e2593ced120c4a98b9ed7e28b132445642)
+++ firmware/App/Modes/BloodPrime.c	(.../BloodPrime.c)	(revision 931ca8779b64aa8bb68aa26d1f631d040a753007)
@@ -128,21 +128,35 @@
     setValvePosition( VDI, VALVE_POSITION_C_CLOSE );
     setValvePosition( VDO, VALVE_POSITION_C_CLOSE );
     setValvePosition( VBA, VALVE_POSITION_B_OPEN );
-    setValvePosition( VBV, VALVE_POSITION_B_OPEN );
 
     // Ensure dialysate outlet and Heparin pumps are stopped
     signalDialOutPumpHardStop();
     stopSyringePump();
 
     // start blood and dialysate inlet pumps
-    setBloodPumpTargetFlowRate( (U32)bloodPrimeRampFlowRate_mL_min, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
     setDialInPumpTargetFlowRate( DIALYSATE_FLOW_RATE_FOR_RECIRC, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
     cmdStartDGTrimmerHeater();
     setCurrentSubState( (U32)bloodPrimeState );
 
     // Start air trap control
     startAirTrapControl();
 
+    // make sure air trap fill is handled right
+    if ( TRUE == isAirTrapFillInProgress() )
+    {
+        // set BP to air trap fill rate if air trap fill has been initiated
+        setBloodPumpTargetFlowRate( AIR_TRAP_FILL_BLOOD_FLOW_RATE, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
+        // close VBV for fill
+        setValvePosition( VBV, VALVE_POSITION_C_CLOSE );
+    }
+    else
+    {
+        // Start blood pump at prescribed flow rate
+        setBloodPumpTargetFlowRate( (U32)bloodPrimeRampFlowRate_mL_min, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
+        // re-open VBV for blood recirculation
+        setValvePosition( VBV, VALVE_POSITION_B_OPEN );
+    }
+
     // Set user alarm recovery actions allowed in this sub-mode
     setAlarmUserActionEnabled( ALARM_USER_ACTION_RESUME, TRUE );
     setAlarmUserActionEnabled( ALARM_USER_ACTION_RINSEBACK, TRUE );
@@ -233,7 +247,7 @@
     if ( ( airTrapFillInProgress != TRUE ) && ( TRUE == isAirTrapFillInProgress() ) )
     {
         // set BP to air trap fill rate if air trap fill has been initiated
-        setBloodPumpTargetFlowRate( AIR_TRAP_FILL_BLOOD_FLOW_RATE, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
+        setBloodPumpTargetFlowRate( AIR_TRAP_FILL_BLOOD_FLOW_RATE, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
         // close VBV for fill
         setValvePosition( VBV, VALVE_POSITION_C_CLOSE );
     }