Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r1d44cf33cf4461b81b19a8ab0e402c609649786b -r388a6f1cf7661a973b0b08c2eeb4de30522c1e88
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 1d44cf33cf4461b81b19a8ab0e402c609649786b)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 388a6f1cf7661a973b0b08c2eeb4de30522c1e88)
@@ -943,18 +943,25 @@
  *************************************************************************/
 BOOL handleStartStopPrimaryHeater( MESSAGE_T * message )
 {
-    BOOL result;
-    U32 heaterStatus = message->payload[0];
+    BOOL result = FALSE;
 
-    if ( heaterStatus == 1 )
+    if ( message->hdr.payloadLen == sizeof(U32) )
     {
-        result = startPrimaryHeater();
+        BOOL startingHeater;
+
+        memcpy( &startingHeater, message->payload, sizeof(U32) );
+
+        if ( TRUE == startingHeater )
+        {
+            result = startPrimaryHeater();
+        }
+        else
+        {
+            stopPrimaryHeater();
+            result = TRUE;
+        }
     }
-    else
-    {
-        stopPrimaryHeater();
-        result = TRUE;
-    }
+    sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_DG_2_HD, result );
 
     return result;
 }