1. A thermostat for communicating with a remote maintenance server, said thermostat being configured to: receive and send network data from and to the remote maintenance server; receive and send remote controller data from and to a remote controller; receive and send appliance data from and to at least one appliance; and generate a request for appliance data from the at least one appliance to receive appliance data from the at least one appliance in response to the request for appliance data, wherein the at least one appliance corresponds to at least one of a heating, ventilation and air conditioning (HVAC) system, a domestic heating device, an air conditioning unit, a ventilation unit, or combinations thereof wherein the thermostat is further configured to store the appliance data over time and to predict an appliance error by comparing the stored appliance data over time with reference appliance data.