Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r6330949b9dd72e81c3a8405617f27df98acfc3e6 -r5ecdab32d9d42bfda6458b395f32ba9da447a670
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 6330949b9dd72e81c3a8405617f27df98acfc3e6)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 5ecdab32d9d42bfda6458b395f32ba9da447a670)
@@ -589,9 +589,11 @@
  * The startDGHeatDisinfect function starts heat disinfect mode.
  * @details Inputs: standbyState
  * @details Outputs: none
+ * @param isPassive: boolean flag to indicate whether this is passive cool heat
+ * or active cool heat disinfect
  * @return: TRUE if the switch was successful
  *************************************************************************/
-BOOL startDGHeatDisinfect( void )
+BOOL startDGHeatDisinfect( BOOL isPassive )
 {
     BOOL status = FALSE;
 
@@ -605,7 +607,7 @@
 
         getNVRecord2Driver( GET_USAGE_RECORD, (U08*)&usageInfo, sizeof( DG_USAGE_INFO_RECORD_T ), 0, ALARM_ID_NO_ALARM );
 
-        cmdResponse.commandID  = DG_CMD_START_HEAT_DISINFECT;
+        cmdResponse.commandID  = ( FALSE == isPassive ? DG_CMD_START_HEAT_DISINFECT_ACTIVE_COOL : DG_CMD_START_HEAT_DISINFECT_PASSIVE_COOL );
         cmdResponse.rejected   = FALSE;
         cmdResponse.rejectCode = DG_CMD_REQUEST_REJECT_REASON_NONE;
 
@@ -666,7 +668,7 @@
 
         getNVRecord2Driver( GET_USAGE_RECORD, (U08*)&usageInfo, sizeof( DG_USAGE_INFO_RECORD_T ), 0, ALARM_ID_NO_ALARM );
 
-        cmdResponse.commandID  = DG_CMD_START_HEAT_DISINFECT;
+        cmdResponse.commandID  = DG_CMD_START_ACTIVE_COOL;
         cmdResponse.rejected   = FALSE;
         cmdResponse.rejectCode = DG_CMD_REQUEST_REJECT_REASON_NONE;
 
Index: firmware/App/Modes/ModeStandby.h
===================================================================
diff -u -r7d4711edd7b40cd3e29f43e766f79a8a09586fe9 -r5ecdab32d9d42bfda6458b395f32ba9da447a670
--- firmware/App/Modes/ModeStandby.h	(.../ModeStandby.h)	(revision 7d4711edd7b40cd3e29f43e766f79a8a09586fe9)
+++ firmware/App/Modes/ModeStandby.h	(.../ModeStandby.h)	(revision 5ecdab32d9d42bfda6458b395f32ba9da447a670)
@@ -49,7 +49,7 @@
 
 BOOL signalAbortWaterSampling( void );                  // HD signal to abort water sampling.
 BOOL startDGFlush( void );                              // HD start flush mode
-BOOL startDGHeatDisinfect( void );                      // HD start heat disinfect mode
+BOOL startDGHeatDisinfect( BOOL isPassive );            // HD start heat disinfect mode
 BOOL startDGHeatDisinfectActiveCool( void );
 DG_STANDBY_MODE_STATE_T getCurrentStandbyState( void ); // get the current state of the standby mode.
 
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -rab9597daa82d8e4575a8bb1fd8438ac301b85d44 -r5ecdab32d9d42bfda6458b395f32ba9da447a670
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision ab9597daa82d8e4575a8bb1fd8438ac301b85d44)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 5ecdab32d9d42bfda6458b395f32ba9da447a670)
@@ -1285,7 +1285,7 @@
         if ( TRUE == startingDGHeatDisinfect )
         {
             setActiveOrPassiveHeatDisinfectStatus( FALSE );
-            status = startDGHeatDisinfect();
+            status = startDGHeatDisinfect( FALSE );
         }
         else
         {
@@ -1984,19 +1984,8 @@
 
     if ( message->hdr.payloadLen == sizeof(U32) )
     {
-        BOOL startingDGNocturnalHeatDisinfect;
-
-        memcpy( &startingDGNocturnalHeatDisinfect, message->payload, sizeof(U32) );
-
-        if ( TRUE == startingDGNocturnalHeatDisinfect )
-        {
-            setActiveOrPassiveHeatDisinfectStatus( TRUE );
-            status = startDGHeatDisinfect();
-        }
-        else
-        {
-            status = startDGHeatDisinfect();
-        }
+        setActiveOrPassiveHeatDisinfectStatus( TRUE );
+        status = startDGHeatDisinfect( TRUE );
     }
 
     sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_DG_2_HD, status );