Common signs that a heat pump needs repair include a lack of heat, strange noises, strange smells, and poor airflow. Additionally, a malfunctioning thermostat, a frozen evaporator coil, a refrigerant leak, a clogged air filter, or a malfunctioning compressor are all possible indication that something is wrong with your heat pump and it needs repair. If you notice any of these issues, it’s best to call a professional for a diagnosis and repair.