We are still learning about how these work and fail sometimes. To be certain, your thermostat batteriesnwill periodically fail. These are always the first thing to check if screen is blank. Keep at least two AAnbatteries around to replace. Carefully pull face cover toward you from its bottom; and lift cover off twonslots at top of thermostat. Be sure to install batteries in correct direction. Hook face plate at top ofnthermostat and gently push bottom in. It should now work.nIf the screen stops at a time and temperature; try the reset button on the back side of the face plate (itnis white). It will take a minute; but you may get a full screen and function. You will have to reset all yournsettings starting with “Day and Time.”nProgramming: Lower front panel of cover. Turn dial to “set….” Usually start with Set “Day and Time”;nand then do “Set Weekdays” and “Set Weekends.” When setting time, be sure to get the day andnam/pm right. Whatever is blinking can be modified by pushing arrows up or down. To move to nextnsetting, push “Next” button and next setting will blink. Turn dial to do next settings. When all is set, turnndial to “Run.” If you did everything right, the thermostat should show the correct day, time andntemperature setting. NOTE: Thermostat time needs to be reset for Daylight Savings Time twice per year.nTemporary changes to add heat or cool for at least two hours can be done by simply pushing the downnarrow a few degrees lower than current temp reading on cool setting for more cool; or pushing up arrowna few degrees higher than current temp reading on heat setting for more heat. Good Luck!