Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -rb6b733b8d1f25bc2dbe2a94c620cd80aa3ae06f7 -rc0445144841904d5a6ea9d37af639e138e6a86b0
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision b6b733b8d1f25bc2dbe2a94c620cd80aa3ae06f7)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision c0445144841904d5a6ea9d37af639e138e6a86b0)
@@ -268,6 +268,29 @@
 
 /*********************************************************************//**
  * @brief
+ * The signalStartPrime function signals the prime sub-mode the user requested
+ * to start priming operation.
+ * @details Inputs: none
+ * @details Outputs: primeStartRequested
+ * @return none
+ *************************************************************************/
+void signalStartPrime( void )
+{
+    BOOL accepted = FALSE;
+    REQUEST_REJECT_REASON_CODE_T rejReason = REQUEST_REJECT_REASON_NOT_ALLOWED_IN_CURRENT_MODE;
+
+    if ( HD_PRIME_WAIT_FOR_USER_START_STATE == currentPrimeState )
+    {
+        primeStartRequested = TRUE;
+        accepted = TRUE;
+        rejReason = REQUEST_REJECT_REASON_NONE;
+    }
+
+    sendStartPrimeCmdResponse( accepted, rejReason );
+}
+
+/*********************************************************************//**
+ * @brief
  * The signalResumePrime function signals the prime sub-mode to resume
  * previous operation.
  * @details Inputs: none
@@ -301,8 +324,7 @@
  *************************************************************************/
 static void resetPrimeFlags( void )
 {
-    // TODO: set to false after integration with UI
-    primeStartRequested = TRUE;
+    primeStartRequested = FALSE;
     primeResumeRequested = FALSE;
     primeStopRequested = FALSE;
 }
@@ -349,7 +371,6 @@
     if ( ++primeStatusBroadcastTimerCounter >= PRIME_DATA_PUB_INTERVAL )
     {
         PRIMING_DATA_PAYLOAD_T primeData;
-        primeData.currentPrimeState = currentPrimeState;
         primeData.totalTime         = MAX_PRIME_TIME;
         primeData.remainingTime     = MAX_PRIME_TIME - elapsedPrimeTimeInSecs;
 
Index: firmware/App/Modes/Prime.h
===================================================================
diff -u -rb6b733b8d1f25bc2dbe2a94c620cd80aa3ae06f7 -rc0445144841904d5a6ea9d37af639e138e6a86b0
--- firmware/App/Modes/Prime.h	(.../Prime.h)	(revision b6b733b8d1f25bc2dbe2a94c620cd80aa3ae06f7)
+++ firmware/App/Modes/Prime.h	(.../Prime.h)	(revision c0445144841904d5a6ea9d37af639e138e6a86b0)
@@ -37,7 +37,6 @@
 /// Payload record structure for a priming status data broadcast message.
 typedef struct
 {
-    U32 currentPrimeState;      ///< Current state of priming.
     U32 remainingTime;          ///< Remaining time for priming in seconds.
     U32 totalTime;              ///< Total priming time in seconds.
 } PRIMING_DATA_PAYLOAD_T;
@@ -53,6 +52,7 @@
 U32 getPrimeState( void );
 BOOL isPrimeCompleted( void );
 
+void signalStartPrime( void );
 void signalResumePrime( void );
 void signalStopPrime( void );
 
Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r401c4027b0e59182771f0c620465b34579f203f5 -rc0445144841904d5a6ea9d37af639e138e6a86b0
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 401c4027b0e59182771f0c620465b34579f203f5)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision c0445144841904d5a6ea9d37af639e138e6a86b0)
@@ -1199,6 +1199,18 @@
             handleSampleWaterCmd( message );
             break;
 
+        case MSG_ID_UI_SAMPLE_WATER_RESULT:
+            handleSampleWaterResult( message );
+            break;
+
+        case MSG_ID_UI_INSTALLATION_CONFIRM:
+            handleInstallationConfirm( message );
+            break;
+
+        case MSG_ID_UI_START_PRIME_REQUEST:
+            handleStartPrimeCmd( message );
+            break;
+
         case MSG_ID_DG_COMMAND_RESPONSE:
             handleDGCmdResp( message );
             break;
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -rbbf4e1a170f66ce07af12908a1d0fe101a934e9e -rc0445144841904d5a6ea9d37af639e138e6a86b0
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision bbf4e1a170f66ce07af12908a1d0fe101a934e9e)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision c0445144841904d5a6ea9d37af639e138e6a86b0)
@@ -587,6 +587,35 @@
 {
     signalUserConfirmInstallation();
 }
+
+/*********************************************************************//**
+ * @brief
+ * The handlePrimingStartCmd function handles user confirms disposable
+ * installation msg from the UI.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none.
+ *************************************************************************/
+void handleStartPrimeCmd( MESSAGE_T *message )
+{
+    signalStartPrime();
+}
+
+/*********************************************************************//**
+ * @brief
+ * The sendStartPrimeCmdResponse function constructs a start prime user action
+ * response to the UI and queues the msg for transmit on the appropriate CAN channel.
+ * @details Inputs: none
+ * @details Outputs: Start prime command response msg constructed and queued.
+ * @param accepted T/F - was sample water request accepted?
+ * @param reason reason why request was rejected (or zero if accepted)
+ * @return TRUE if msg successfully queued for transmit, FALSE if not
+ *************************************************************************/
+BOOL sendStartPrimeCmdResponse( BOOL accepted, U32 reason )
+{
+    return sendUIResponseMsg( MSG_ID_HD_START_PRIME_REQUEST_RESPONSE, accepted, reason );
+}
 
 /*********************************************************************//**
  * @brief
Index: firmware/App/Services/SystemCommMessages.h
===================================================================
diff -u -rbbf4e1a170f66ce07af12908a1d0fe101a934e9e -rc0445144841904d5a6ea9d37af639e138e6a86b0
--- firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision bbf4e1a170f66ce07af12908a1d0fe101a934e9e)
+++ firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision c0445144841904d5a6ea9d37af639e138e6a86b0)
@@ -170,6 +170,12 @@
 // MSG_ID_UI_INSTALLATION_CONFIRM
 void handleInstallationConfirm( MESSAGE_T *message );
 
+// MSG_ID_UI_START_PRIME_REQUEST
+void handleStartPrimeCmd( MESSAGE_T *message );
+
+// MSG_ID_HD_START_PRIME_REQUEST_RESPONSE
+BOOL sendStartPrimeCmdResponse( BOOL accepted, U32 reason );
+
 // *********** public DG command functions **********
 
 // MSG_ID_SET_DG_DIALYSATE_TEMP_TARGETS