I have two independant units and often compare their operation. The unit is question is not as efficient; and the heated or cooled air is typically 5-7 degrees different. In the case of heating, the air is 7 degrees cooler than the other unit.
One example of erratic operation is, on a 40 degree morning, the outside condenser started up and was making clicking noises. Those noises corresponded to a blinking green AuxHeat light on the thermostat. After about five minutes the clicking and blinking light stopped, and the unit ran normally.
Another case was after the heater was running for about 7 minutes, the outside condenser fan shut off and the unit made a buzzing noise; but the inside air handler fan continued to run and force air for another 2 minutes.
The unit in question is a 3 ton Carrier with a attic mounted air handler.
Thanks for any advice.