Yes I am using the checker and no the site is not in maintenance mode.
HTTP Status Code: 503 Service Unavailable Headers: Array ( [date] => Thu, 18 Sep 2014 18:20:33 GMT [server] => Apache/2 [x-powered-by] => PHP/5.3.28 [set-cookie] => PHPSESSID=bdkmbhqkl7avi1vl2upb19k962; path=/ [expires] => Sat, 26 Jul 1997 05:00:00 GMT [cache-control] => private, no-cache, no-store, proxy-revalidate, no-transform [pragma] => no-cache [vary] => Cookie,Accept-Encoding,User-Agent [status] => 503 Service Temporarily Unavailable [retry-after] => -435761 [content-length] => 3257 [connection] => close [content-type] => text/html; charset=UTF-8 )