I have a Trane heat pump and XT500C thermostat. Currently, the heat and cool temperature set points can not be any closer than 4 deg. Is there a way to change this to 2 deg? I live in Florida and in sping and fall (and winter) it is cool in the morning requiring heat and then warms up enough by afternoon requiring cool. With the 4 deg temp setting we are always having to tweak the temp. Thanks.