A multiple language user interface system for a thermal comfort controller. The user interface system has a central processing unit coupled to a memory, a language selector and a touch sensitive display unit. The memory can store at least one user interface object and at least one control algorithm. In some embodiments, the user interface system also has a network interface for connecting to the Internet or other network. In some embodiments, the first time the user interface system is powered-up after installation, a first set of user interface objects are displayed on the display unit and the user selects a preferred language. Once a preferred language is chosen, user interface objects can be loaded into the memory and the display unit will display the user interface objects in the preferred language. In some embodiments, control algorithms are loaded into memory.