Floor heating thermostat&Digital thermostat&Underfloor heating thermostat This floor heating thermostat is a combination model allowing you to choose between 3 different modes: A,AF and F mode A Mode: Air only, with built in sensor. This mode is designed to control the ambient temperature with one temperature sensor located in the control module. The sensor detects the room temperature, when the room temperature reaches the set-point, the heating system will be closedAF Mode: Air and floor, with both built in and remote sensor. This mode is designed to use a floor sensor to control the room temperature. The model has two temperature sensors. One is built-in sensor located at inside of the thermostat, controls the ambient temperature. The other one is installed in the floor to detect the floor temperature. F Mode: Floor only, with remote sensor. This mode is designed to control floor heating systems. It has one temperature sensor installed in the floor (sensor is connected to the power base).When the floor temperature reaches the set-point, the heating system will be closed Specifications: 1) Large LCD screen, attractive design 2) Easy to program and install 3) Protected memory, no batteries required 4) Fahrenheit and centigrade temperature mode selectable 5) Comfort / economy / vacation set-point selectable 6) 4 daily programs with separate 7 day settings 7) Automatic memory with manual override switch 8) Clock display 9) Week day display 10) Energy saving 11) Supplied with floor sensor 12) Remote control optional 13) Blue back light optional. Ordering Code AE-Y309 -- Standard model AE-Y309L -- With backlight function AE-Y309Y -- With remote control function (need remote controller which should be ordered separately) AE-Y309YL--With both backlight and remote function.