One thing I found a little baffling when I started using spring boot was that the health pages returned 200 regardless of your 'Status'. So 'DOWN' would return a 200 with the actual information in a JSON payload. This means any monitoring system needs to parse the JSON rather than just know based on the HTTP status code.
Finally for Spring Boot 1.1 you can override this! For example if you want DOWN to be a 500, then add the following to your application properties file.