Tekmar 479 tN4 User Switch Pre-Programmed The tekmarNet 4 User Switch 479 is a simple 3 button switch that provides an easy way to override system temperatures. This user switch is a must have for any tekmarNet system. Using tekmarNet 4 to communicate with any other compatible tekmarNet devices, the 479 User Switch allows the owner to override their entire tekmarNet system, and offers the potential for significant energy savings. With the push of a button, the user can place all thermostats and boiler controls into an away" state and take advantage of saving energy when the building is not being used.