Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -r6f5bb3935a079cf48c836b2227db430c069bac40 -rb1a931b5151819b00f9bc7bb7d352805c3e55015
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision 6f5bb3935a079cf48c836b2227db430c069bac40)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision b1a931b5151819b00f9bc7bb7d352805c3e55015)
@@ -784,20 +784,7 @@
         if ( TRUE == didTimeout( steadyVolumeSamplingStartTime, LOAD_CELL_STEADY_VOLUME_SAMPLING_TIME ) )
         {
             F32 currentReservoirVolume = getLoadCellWeight( LOAD_CELL_RESERVOIR_1_PRIMARY );
-            F32 venPres                = getFilteredVenousPressure();
 
-            // Adjust DPo speed to maintain venous pressure if necessary
-            if ( venPres > ( primeDialysateDialyzerStartVenPres + PRESSURE_OFFSET_DIALYSATE_PRIME_MMHG ) )
-            {
-                primeDialysateDialyzerDPoRate += DPO_RATE_STEP_PER_SEC_DIALYSATE_PRIME_ML_MIN;
-                setDialOutPumpTargetRate( primeDialysateDialyzerDPoRate, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
-            }
-            else if ( venPres < ( primeDialysateDialyzerStartVenPres - PRESSURE_OFFSET_DIALYSATE_PRIME_MMHG ) )
-            {
-                primeDialysateDialyzerDPoRate -= DPO_RATE_STEP_PER_SEC_DIALYSATE_PRIME_ML_MIN;
-                setDialOutPumpTargetRate( primeDialysateDialyzerDPoRate, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
-            }
-
             if ( currentReservoirVolume >= ( minimumReservoirVolume - STEADY_VOLUME_DIALYSATE_PRIME_HISTERESIS_ML ) )
             {
                 if ( ++steadyVolumeCount >= STEADY_VOLUME_COUNT_SEC )
@@ -813,12 +800,24 @@
             {
                 minimumReservoirVolume = currentReservoirVolume;
             }
-
-            steadyVolumeSamplingStartTime = getMSTimerCount();       // re-armed the timer for the next dVolume/dt check
         }
     }
-    else
+
+    // Adjust DPo speed to maintain venous pressure if necessary (re-using 1 sec steady volume timer to do this @ 1Hz)
+    if ( TRUE == didTimeout( steadyVolumeSamplingStartTime, LOAD_CELL_STEADY_VOLUME_SAMPLING_TIME ) )
     {
+        F32 venPres                = getFilteredVenousPressure();
+
+        if ( venPres > ( primeDialysateDialyzerStartVenPres + PRESSURE_OFFSET_DIALYSATE_PRIME_MMHG ) )
+        {
+            primeDialysateDialyzerDPoRate += DPO_RATE_STEP_PER_SEC_DIALYSATE_PRIME_ML_MIN;
+            setDialOutPumpTargetRate( primeDialysateDialyzerDPoRate, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
+        }
+        else if ( venPres < ( primeDialysateDialyzerStartVenPres - PRESSURE_OFFSET_DIALYSATE_PRIME_MMHG ) )
+        {
+            primeDialysateDialyzerDPoRate -= DPO_RATE_STEP_PER_SEC_DIALYSATE_PRIME_ML_MIN;
+            setDialOutPumpTargetRate( primeDialysateDialyzerDPoRate, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
+        }
         steadyVolumeSamplingStartTime = getMSTimerCount();
     }