A system for remotely monitoring and controlling an HVAC device includes a server which receives queries from an entry device and data from the HVAC device. Databases with information regarding the location and status of the HVAC devices reside on the server, as does a user name/password file, instead of in the entry device or the HVAC controller. Connection is provided over various communications links including the Internet, POTS, and GSM networks. A user with an entry device such as a handheld computer or cell phone using wireless access protocol (WAP) can change settings, obtain diagnostic information, and receive alarm messages about a plurality of HVAC devices.