I think I am having problems with the programmed scheduler aspect of the thermostat. I am trying to cool my house and periodically it changes the set temp to 82 when I have it on 77 or whatever. This happens during almost every night and also during the day at some unknown interval. We have just purchased this home and no manual was left for the thermostat RTH7500D. I have looked at the manual on line but nothing is mentioned regarding the scheduling features. Can you help? jim