Yes, infact, if you have the old mercury thermostat, it is recommended to get a new digital thermostat to keep your cooling/heating comfort to the optimal level. It is fairly easy to replace a thermostat. Removw the covering for your old thermostat and mask tape each wires, writing down their corresponding letters with each. Once done, unscrew the thermianal and remove the wires. Then unscrew the thermostat wall mount and remove it. Screw in your new thermostat and connect the wires to their respective letters. Put the thermostat cover back on and you should be good to go.