Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r9b6d9a0db373b39c3d04dd07516fde59b292bbc5 -r4828ff8bd5b5ff97f36de33101d8ca4b9e54bfa1
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 9b6d9a0db373b39c3d04dd07516fde59b292bbc5)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 4828ff8bd5b5ff97f36de33101d8ca4b9e54bfa1)
@@ -141,6 +141,7 @@
 static PRE_TREATMENT_RESERVOIR_MGMT_STATE_T handlePreTreatmentReservoirMgmtFillCompleteState( void );
 static PRE_TREATMENT_RESERVOIR_MGMT_STATE_T handlePreTreatmentReservoirMgmtRequestReservoirSwitchState( void );
 static PRE_TREATMENT_RESERVOIR_MGMT_STATE_T handlePreTreatmentReservoirMgmtWaitReservoirSwitchState( void );
+static void handleDGParkConcentratePumpsCmdRespState( void );
 static U32 getPreTreatmentFillVolume( DG_RESERVOIR_ID_T inactiveRes );
 static void setPreTreatmentHeatingParams( F32 targetTempC, U32 targetVolML, F32 targetFillFlowLPM, U32 dialysateFlowMLPM );
 
@@ -1205,6 +1206,8 @@
             break;
 
         case PRE_TREATMENT_RESERVOIR_MGMT_COMPLETE_STATE:
+            // retry the DG park concentrate pump request command if previous request was failed.
+            handleDGParkConcentratePumpsCmdRespState();
             break;
 
         default:
@@ -1544,6 +1547,30 @@
 
 /*********************************************************************//**
  * @brief
+ * The handleDGParkConcentratePumpsCmdRespState function checks
+ * Park DG concentrate pump command request sent was successfully handled or not.
+ * on failure, retry the DG Concentrate pumps park command request.
+ * @details Inputs: DG park concentrate pump request command response
+ * @details Outputs: retry park command on failure
+ * @return none
+ *************************************************************************/
+static void handleDGParkConcentratePumpsCmdRespState( void )
+{
+    DG_CMD_RESPONSE_T dgCmdResp;
+
+    // Check DG response to park concentrate pumps command
+    if ( TRUE == getDGCommandResponse( DG_CMD_PARK_CONCENTRATE_PUMPS, &dgCmdResp ) )
+    {
+        if ( DG_CMD_REQUEST_REJECT_REASON_NONE != dgCmdResp.rejectCode )
+        {
+            // retry park concentrate pumps command request to DG
+            cmdDGParkConcentratePumps();
+        }
+    }
+}
+
+/*********************************************************************//**
+ * @brief
  * The getPreTreatmentFillVolume function determines which volume to fill
  * the inactive reservoir.
  * @details Inputs: reservoirStatus[]