Carrier Infinity HVAC Thermostat Temp not chaning
I have a carrier Infinity Gas furnace and AC system. The problem we are having is that it is not very cool in the house, relative to outside temp despite very cool Temps for N. VA at this time(only been mid to high 80's). The Thermostat is a "User Interface" that has lot more options/setting than just schedule and temp. We have had HVAC guys come out and the unit is working fine. The temp going in and coming out are within parameters. Despite running the AC 24/7 and having it set at 70(for testing purposes) we can never get the thermostat to drop below 75. It always reads between 75-80. I have put a thermometer on the thermostat and the thermometer will adjust more than the thermostat. I might sound crazy, but for testing purposes, I've TRIED to get the temp in the house to "freezing" mode, like below 70 and I can not. it is almost like the system has a mind of its own and won't do what I tell it to do.
The system is 5 years old. We bought the house a month ago, so I have no history on how it was installed or know how it works. The previous owner was in his 80's and i don't think he minded the temp being 78+.
Any suggestions on how this "advance" system works would be great because the HVAC company that comes out seems not to know anything about computer controlled HVAC and never looks at the user interface.