Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -re3a42336d697af9e7a5c980db0456e72bc949c31 -r07589ffe861c73f9095c6b1536ec97ec2238fbce
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision e3a42336d697af9e7a5c980db0456e72bc949c31)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 07589ffe861c73f9095c6b1536ec97ec2238fbce)
@@ -86,10 +86,8 @@
 #define RSRVRS_DRAIN_TIMEOUT_MS                    ( 2 * SEC_PER_MIN * MS_PER_SECOND )                         ///< Reservoirs 1 & 2 drain timeout in ms.
 
 // Fill and heat water
-//wjb#define HEAT_DISINFECT_TARGET_TEMPERATURE_C        82.0F                                                       ///< Heat disinfect target water temperature in C.
-//wjb#define HEAT_DISINFECT_START_TEMPERATURE_C         81.0F                                                       ///< Heat disinfect minimum acceptable temperature in C.
-#define HEAT_DISINFECT_TARGET_TEMPERATURE_C        52.0F                                                       ///< Heat disinfect target water temperature in C.
-#define HEAT_DISINFECT_START_TEMPERATURE_C         51.0F                                                       ///< Heat disinfect minimum acceptable temperature in C.
+#define HEAT_DISINFECT_TARGET_TEMPERATURE_C        82.0F                                                       ///< Heat disinfect target water temperature in C.
+#define HEAT_DISINFECT_START_TEMPERATURE_C         81.0F                                                       ///< Heat disinfect minimum acceptable temperature in C.
 
 // R1 to R2 & R2 to R1 heat disinfect circulation
 #define HEAT_DISINFECT_TARGET_RO_FLOW_LPM          1.3F                                                        ///< Heat disinfect target RO flow rate in L/min.
@@ -144,6 +142,13 @@
     NUM_OF_HEAT_DISINFECT_STATUS                                                                               ///< Number of heat disinfect status.
 } HEAT_DISINFECT_STATUS_T;
 
+/// Non-volatile write structure
+typedef struct
+{
+    BOOL hasDisStatusBeenWrittenToNV;                                                                          ///< Boolean flag to indicate whether the disinfect status been written to NV or not.
+    BOOL hasDisCompleteDateBeenWrittenToNV;                                                                    ///< Boolean flag to indicate whether the disinfect complete date been written to NV or not.
+} DISINFECT_NV_OPS_T;
+
 // ********** private data **********
 
 static DG_HEAT_DISINFECT_STATE_T heatDisinfectState = DG_HEAT_DISINFECT_STATE_START;                           ///< Current active heat disinfect state.
@@ -173,6 +178,7 @@
 static U32 targetDisinfectTime = 0;                                                                            ///< Target disinfect time.
 static BOOL haveDrainParamsBeenInit[ NUM_OF_DG_RESERVOIRS ];                                                   ///< Boolean flag to indicate whether the drain parameters have been reset or not.
 static U32 tempGradOutOfRangeTimer;                                                                            ///< Temperature gradient out of range start timer.
+static DISINFECT_NV_OPS_T disinfectNVOps;                                                                      ///< Disinfect non-volatile memory operations.
 
 // ********** private function prototypes **********
 
@@ -218,34 +224,37 @@
  * R1HeatDisinfectVol, R2HeatDisinfectVol, overallHeatDisinfectTimer,
  * cancellationMode, rsrvrFillStableTimeCounter, prevHeatDisinfectState
  * isPartialDisinfectInProgress, isDrainPumpOnInMixDrain,
- * ROFCoolingTimer, targetDisinfectTime, concentratePumpsPrimeTimer,
- * haveDrainParamsBeenInit, tempGradOutOfRangeTimer
+ * hasROFCirculationBeenStarted, ROFCirculationTimer, targetDisinfectTime
+ * ROFCirculationCoolingCounter, concentratePumpsPrimeTimer,
+ * haveDrainParamsBeenInit, tempGradOutOfRangeTimer, disinfectNVOps
  * @return none
  *************************************************************************/
 void initHeatDisinfectMode( void )
 {
-    heatDisinfectState                          = DG_HEAT_DISINFECT_STATE_START;
-    prevHeatDisinfectState                      = DG_HEAT_DISINFECT_STATE_START;
-    heatDisinfectUIState                        = HEAT_DISINFECT_UI_STATE_NOT_RUNNING;
-    stateTimer                                  = 0;
-    isThisLastDrain                             = FALSE;
-    stateTrialCounter                           = 0;
-    areTempSensorsInRange                       = FALSE;
-    rsrvr1Status                                = NUM_OF_DG_RESERVOIR_STATUS;
-    rsrvr2Status                                = NUM_OF_DG_RESERVOIR_STATUS;
-    R1HeatDisinfectVol                          = 0.0;
-    R2HeatDisinfectVol                          = 0.0;
-    overallHeatDisinfectTimer                   = 0;
-    cancellationMode                            = CANCELLATION_MODE_NONE;
-    rsrvrFillStableTimeCounter                  = 0;
-    isPartialDisinfectInProgress                = FALSE;
-    isDrainPumpInMixDrainOn                     = FALSE;
-    ROFCoolingTimer                             = 0;
-    concentratePumpsPrimeTimer                  = 0;
-    targetDisinfectTime                         = 0;
-    haveDrainParamsBeenInit[ DG_RESERVOIR_1 ]   = FALSE;
-    haveDrainParamsBeenInit[ DG_RESERVOIR_2 ]   = FALSE;
-    tempGradOutOfRangeTimer                     = 0;
+    heatDisinfectState                               = DG_HEAT_DISINFECT_STATE_START;
+    prevHeatDisinfectState                           = DG_HEAT_DISINFECT_STATE_START;
+    heatDisinfectUIState                             = HEAT_DISINFECT_UI_STATE_NOT_RUNNING;
+    stateTimer                                       = 0;
+    isThisLastDrain                                  = FALSE;
+    stateTrialCounter                                = 0;
+    areTempSensorsInRange                            = FALSE;
+    rsrvr1Status                                     = NUM_OF_DG_RESERVOIR_STATUS;
+    rsrvr2Status                                     = NUM_OF_DG_RESERVOIR_STATUS;
+    R1HeatDisinfectVol                               = 0.0;
+    R2HeatDisinfectVol                               = 0.0;
+    overallHeatDisinfectTimer                        = 0;
+    cancellationMode                                 = CANCELLATION_MODE_NONE;
+    rsrvrFillStableTimeCounter                       = 0;
+    isPartialDisinfectInProgress                     = FALSE;
+    isDrainPumpInMixDrainOn                          = FALSE;
+    ROFCoolingTimer                                  = 0;
+    concentratePumpsPrimeTimer                       = 0;
+    targetDisinfectTime                              = 0;
+    haveDrainParamsBeenInit[ DG_RESERVOIR_1 ]        = FALSE;
+    haveDrainParamsBeenInit[ DG_RESERVOIR_2 ]        = FALSE;
+    tempGradOutOfRangeTimer                          = 0;
+    disinfectNVOps.hasDisCompleteDateBeenWrittenToNV = FALSE;
+    disinfectNVOps.hasDisStatusBeenWrittenToNV       = FALSE;
 }
 
 /*********************************************************************//**
@@ -1275,6 +1284,8 @@
     // Set the heat disinfect UI state
     heatDisinfectUIState = HEAT_DISINFECT_UI_STATE_COOL_DOWN_DEVICE;
 
+    writeDisinfectDataToNV();
+
     if ( TRUE == didTimeout( stateTimer, POST_HEAT_DISINFECT_WAIT_TIME_MS ) )
     {
         // Stop the drain pump and the RO pump to exit the closed loop