We had a geothermal system put it our house in October so this is our first winter using it. Last week the temps here in N. Georgia got down to the low 20's and our system could not seem to get above 65 degrees. We set it back to 62 during the day and it comes back on at 5:00 p.m. to 68 degrees but it could never reach that temp. Is this normal???? We have LP gas as auxiliary but it is set to come when temps reach 10 degrees. Any help is appreciated.