Index: firmware/App/Controllers/DialOutFlow.c
===================================================================
diff -u -r2a301437ee7dd8557afcb2203cdcb10991dbb7d8 -r6442d95e1835d25a608dbe5b2d9bc3ea92db771d
--- firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 2a301437ee7dd8557afcb2203cdcb10991dbb7d8)
+++ firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 6442d95e1835d25a608dbe5b2d9bc3ea92db771d)
@@ -48,6 +48,8 @@
 #define DIAL_OUT_DATA_PUB_INTERVAL              ( MS_PER_SECOND / TASK_PRIORITY_INTERVAL )
 /// Interval (ms/task time) at which the dialysate outlet flow is filtered.
 #define DIAL_OUT_FILTER_INTERVAL                ( 100 / TASK_PRIORITY_INTERVAL )
+/// Interval (ms/task time) at which the ultrafiltration flow rate is calculated.
+#define DIAL_OUT_UF_CALC_INTERVAL               ( 1000 / TASK_PRIORITY_INTERVAL )
 
 #define MAX_DIAL_OUT_FLOW_RATE                  700             ///< Maximum dialysate outlet pump flow rate in mL/min.
 #define MIN_DIAL_OUT_FLOW_RATE                  100             ///< Minimum dialysate outlet pump flow rate in mL/min.
@@ -181,6 +183,7 @@
 static F32 ufMeasuredRate = 0.0;                                                            ///< Calculated UF flow rate from measured dialysate flow rate subtracted from estimated dialysate outlet flow rate.
 static F32 dopRateCorrectionOffset = 0.0;                                                   ///< Correction offset for estimated flow rate for dialysate outlet pump.
 
+static U32 ufCalcTimerCtr = 0;                                                              ///< Timer counter for determining when to calculate the ultrafiltration rate.
 static U32 flowFilterTimerCtr = 0;                                                          ///< Timer counter for determining when to add a new sample to the moving average.
 static F64 flowReadings[ SIZE_OF_ROLLING_AVG ];                                             ///< Holds flow samples for a rolling average.
 static U32 flowReadingsIdx = 0;                                                             ///< Index for next sample in rolling average array.
@@ -613,27 +616,33 @@
     // Filter estimated dialysate out flow rate and estimate UF rate if running pump in closed loop mode
     if ( ( TRUE == isDialOutPumpOn ) && ( PUMP_CONTROL_MODE_CLOSED_LOOP == dialOutPumpControlMode ) )
     {
-        if ( ++flowFilterTimerCtr >= DIAL_OUT_FILTER_INTERVAL )
-        {
-            flowFilterTimerCtr = 0;
-            // Calculate DPo flow in mL/min
-            filterDialOutFlowReadings( getMeasuredDialOutPumpMCSpeed() * RPM_2_ML_MIN_CONVERSION );
-            // Calculate UF flow in mL/min
-            if ( DIAL_OUT_PUMP_CONTROL_TO_TARGET_STATE == dialOutPumpState )
-            {
+        if ( DIAL_OUT_PUMP_CONTROL_TO_TARGET_STATE == dialOutPumpState )
+        {   // pump is controlling
+            if ( ++flowFilterTimerCtr >= DIAL_OUT_FILTER_INTERVAL )
+            {   // Calculate DPo flow in mL/min
+                flowFilterTimerCtr = 0;
+                filterDialOutFlowReadings( getMeasuredDialOutPumpMCSpeed() * RPM_2_ML_MIN_CONVERSION );
+            }
+            if ( ++ufCalcTimerCtr >= DIAL_OUT_UF_CALC_INTERVAL )
+            {   // Calculate UF flow in mL/min
+                ufCalcTimerCtr = 0;
                 ufMeasuredRate = dopMeasuredRate - getMeasuredDialInFlowRate();
             }
-            else
-            {   // if we're ramping, calculation won't work so just set to set rate
-                ufMeasuredRate = getCurrentUFSetRate();
-            }
         }
+        else
+        {   // pump is ramping
+            flowFilterTimerCtr = 0;
+            ufCalcTimerCtr     = 0;
+            ufMeasuredRate     = getCurrentUFSetRate();                         // UF calculation won't work while ramping so just set to set UF rate
+            dopMeasuredRate    = getMeasuredDialInFlowRate() + ufMeasuredRate;  // and set flow rate to in flow + set UF rate
+        }
     }
     else
-    {
+    {   // pump is off or in open loop mode
         dopMeasuredRate    = 0.0F;
         ufMeasuredRate     = 0.0F;
         flowFilterTimerCtr = 0;
+        ufCalcTimerCtr     = 0;
     }
 
     // Do not start enforcing checks until out of init/POST mode