that the unit is set to turn on at 79 degrees or lower. if this does not work, check that the thermostat is working. use a different thermostat to check the indoor temperature. you can use one that you have to tell you the outside temperature. just bring it inside and wait for it to adjust to the indoor temperature. if there is a problem with the thermostat, you can buy one at a local hardware store. simply follow the instructions to replace the old one, as it is not difficult.
if cleaning the filters or replacing the thermostat does not have the unit working properly, it is probably time to 