Me and my wife just bought this house,the fella we bought it from had a new furnace installed it's a goodman electric heat pump furnace,it's still under warranty,but instead of calling and having to wait on someone to come out to the house I would like to fix myself,I set the thermostat at 72 but since we've moved in it hasn't gotten above 68,it's in the teens at night,20's during the day,days it'll make it's way up to 68,nights drops into the low 60's,any help will be appreciated.