Index: firmware/App/Modes/OperationModes.c
===================================================================
diff -u -r37a9fd8f15e413db5337371a7d1a1cb65567af7c -r5b448e81db260e5b041699a83c6f2a3faa260ea9
--- firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision 37a9fd8f15e413db5337371a7d1a1cb65567af7c)
+++ firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision 5b448e81db260e5b041699a83c6f2a3faa260ea9)
@@ -26,9 +26,12 @@
 #include "ModePreTreat.h"
 #include "ModeTreatment.h"
 #include "ModePostTreat.h"
+#include "NVDataMgmt.h"
 #include "OperationModes.h"
+#include "RTC.h"
 #include "SystemCommMessages.h"
 #include "TaskGeneral.h"
+#include "Timers.h"
 
 /**
  *  @addtogroup HDOperationModes
@@ -136,6 +139,16 @@
         lastMode = currentMode;
         transitionToNewOperationMode( newMode );
         currentMode = newMode;
+
+        if ( MODE_TREA == currentMode )
+        {
+            // If the current mode is treatment but transitioning to another mode has been requested (including transitioning to fault mode)
+            // it means the treatment is done. Get the elapsed time since the beginning of the treatment and convert it to hours to be written
+            U32 txElapsedTimeMS  = calcTimeSince( getTreatmentStartTimeStamp() );
+            F32 txElapsedTimeHrs = (F32)txElapsedTimeMS / ( MIN_PER_HOUR * SEC_PER_MIN * MS_PER_SECOND );
+            // Write the treatment hours and set the service to be false so the treatment hours is not reset
+            setTxTimeHours( txElapsedTimeHrs, FALSE );
+        }
     }
 
     // Mode specific processing to be done continuously