The present invention relates to a method for monitoring a base device (11), in particular a building or part of a building or a vehicle, by means of a mobile terminal (10), wherein the base device (11) has at least one heating device, in particular with a temperature sensor, comprising the steps: determining a current state of the base device (11) by means of the heating device, in particular comprising determining a current temperature at or in the base device (11) by the temperature sensor of the heating device and/or determining an energy supply of the heating device, checking whether the current state is a normal state or an abnormal state and/or whether the current change in state is a normal change in state or an abnormal change in state, and outputting of corresponding information to the mobile terminal (10) and/or by said mobile terminal, at least when an abnormal state and/or an abnormal change in state is detected.