Puck not starting AC

Hi, I bought 4 pucks and set the ones upstairs to a lower temperature (around 71) and the one in the in laws apartment at a higher temperature (75) because the room is always cold.  Now, the current temperature is at 75-78 where set at 71 and at 68 where set at 75, plus the puck is not starting the AC even with 6-7 degrees difference between the current and desired.  Any help?