A wall mountable connector configured to facilitate a user in removing a first thermostat from the wall mountable connector and installing a new, different second thermostat on the wall mountable connector without having to do any wiring work. The field wires remain coupled to the wall mountable connector, and the wall mountable connector provides the appropriate electrical connections between the field wires and the first and second thermostats. In some cases, the wall mountable connector may include a memory for storing data communicated by a first thermostat, and to communicate the stored data to a subsequently installed second thermostat. In some instances, the first and second thermostats may be selected from a line of compatible thermostats.