Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r5ce2656c662525e10acd1e55f16f7aca5ce9b4d6 -r4cc579577062113856fd266cb65b1ccbe33bb596
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 5ce2656c662525e10acd1e55f16f7aca5ce9b4d6)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 4cc579577062113856fd266cb65b1ccbe33bb596)
@@ -48,6 +48,7 @@
 
 #define DISINFECTS_DATA_PUB_INTERVAL          ( 1 * MS_PER_SECOND / TASK_GENERAL_INTERVAL )    ///< Disinfects data publish interval in counts.
 #define DISINFECTS_TIME_INTERVAL_S            ( 2 * SECONDS_IN_A_DAY )                         ///< HD/DG 2-day service interval in seconds.
+#define FLUSH_TIME_INTERVAL_S                 ( 30 * SEC_PER_MIN * MS_PER_SECOND )             ///< Flush time interval in seconds.
 
 // ********** private data **********
 
@@ -969,27 +970,44 @@
 static BOOL isDGDisinfectValid( void )
 {
     DG_SERVICE_AND_USAGE_DATA_T data;
-    BOOL status = TRUE;
+    BOOL status = FALSE;
 
     getHDVersionDGServiceAndUsageData( &data );
 
     if ( TRUE == data.isDGUsageInfoAviable )
     {
-        if ( TRUE == data.dgUsageInfo.isDisinfected )
-        {
-            U32 chemDisElapsedTimeS    = getRTCTimestamp() - data.dgUsageInfo.lastChemicalDisDateEpoch;
-            BOOL hasChemDisBeenExpired = ( chemDisElapsedTimeS > DISINFECTS_TIME_INTERVAL_S ? TRUE : FALSE );
-            U32 heatDisElapsedTimeS    = getRTCTimestamp() - data.dgUsageInfo.lastHeatDisDateEpoch;
-            BOOL hasHeatDisBeenExpired = ( heatDisElapsedTimeS > DISINFECTS_TIME_INTERVAL_S ? TRUE : FALSE );
+        HD_USAGE_INFO_RECORD_T usageRecord;
+        getNVRecord2Driver( GET_USAGE_RECORD, (U08*)&usageRecord, sizeof( HD_USAGE_INFO_RECORD_T ), 0, ALARM_ID_NO_ALARM );
 
-            if ( ( TRUE == hasChemDisBeenExpired ) && ( TRUE == hasHeatDisBeenExpired ) )
-            {
-                status = FALSE;
-            }
-        }
-        else
+        U32 lastChemCompleteDate      = data.dgUsageInfo.lastChemDisCompleteDateEpoch;
+        U32 lastChemFlushCompleteDate = data.dgUsageInfo.lastChemDisFlushCompleteDateEpoch;
+        U32 lastHeatCompleteDate      = data.dgUsageInfo.lastHeatDisCompleteDateEpoch;
+        U32 lastFlushCompleteDate     = data.dgUsageInfo.lastBasicFlushCompleteDateEpoch;
+        U32 lastStartTxTimeDate       = usageRecord.txLastStartTimeEpoch;
+
+        // Last Treatment Start < Last Heat Disinfect Complete or Last Treatment Start < Last Chem Disinfect Complete so it means at least a heat disinfect
+        // or a chemical disinfect has been done since the last treatment
+        BOOL hasDisBeenDone = ( ( ( lastStartTxTimeDate < lastChemCompleteDate ) || ( lastStartTxTimeDate < lastHeatCompleteDate ) ) ? TRUE : FALSE );
+
+        // Last Chem Disinfect Complete < Current Time – Chem Disinfect Interval, so the chemical disinfect that has been done has not been expired
+        BOOL isChemDisValid = ( lastChemCompleteDate < ( getRTCTimestamp() - DISINFECTS_TIME_INTERVAL_S ) ? TRUE : FALSE );
+
+        // Last Heat Disinfect Complete < Current Time – Heat Disinfect Interval, so the heat disinfect that has been done has not been expired
+        BOOL isHeatDisValid = ( lastHeatCompleteDate < ( getRTCTimestamp() - DISINFECTS_TIME_INTERVAL_S ) ? TRUE : FALSE );
+
+        // Last Chem Flush Complete < Last Chem Disinfect Start, so after running a chemical disinfect, a chemical disinfect flush has been done
+        BOOL isChemFlushComplete = ( lastChemFlushCompleteDate > lastChemCompleteDate ? TRUE : FALSE );
+
+        // If either of the basic flush, heat disinfect, or chemical disinfect flush have been done within the interval, it means the filters have been flushed
+        BOOL isBasicFlushValid   = ( lastFlushCompleteDate     < ( getRTCTimestamp() - FLUSH_TIME_INTERVAL_S ) ? TRUE : TRUE );
+        BOOL isHeatDisFlushValid = ( lastHeatCompleteDate      < ( getRTCTimestamp() - FLUSH_TIME_INTERVAL_S ) ? TRUE : TRUE );
+        BOOL isChemFlushValid    = ( lastChemFlushCompleteDate < ( getRTCTimestamp() - FLUSH_TIME_INTERVAL_S ) ? TRUE : TRUE );
+        BOOL isFlushValid        = ( isBasicFlushValid || isHeatDisFlushValid || isChemFlushValid );
+
+        // If all of the above conditions are true, it means we can start a treatment
+        if ( ( TRUE == hasDisBeenDone ) && ( TRUE == isChemDisValid ) && ( TRUE == isHeatDisValid ) && ( TRUE == isChemFlushComplete ) && ( TRUE == isFlushValid ) )
         {
-            status = FALSE;
+            status = TRUE;
         }
     }
 
@@ -1016,7 +1034,7 @@
 
     if ( TRUE == dgData.isDGServiceRecordAvailable )
     {
-        U32 dgSrvcElapsedTimeS    = getRTCTimestamp() - dgData.dgServiceRecord.lastServiceDateEpoch;
+        U32 dgSrvcElapsedTimeS    = getRTCTimestamp() - dgData.dgServiceRecord.lastServiceEpochDate;
         BOOL hasDGSrvcBeenExpired = ( dgSrvcElapsedTimeS > SERVICE_TIME_INTERVAL_S ? TRUE : FALSE );
         U32 hdSrvcElapsedTimeS    = getRTCTimestamp() - hdServiceRecord.lastServiceEpochDate;
         BOOL hasHDSrvcBeenExpied  = ( hdSrvcElapsedTimeS > SERVICE_TIME_INTERVAL_S ? TRUE : FALSE );