A. This will depend greatly on the model of heat pump and the original installer. The best heat pump in the world will never run right unless it’s installed and commissioned right. A quality heat pump service will result in the heat pump running as a manufacture would have specified. Often filter valves are not in correctly or not at all, heat pumps wired wrong, circulation pump speeds wrong, too much or too little glycol, faulty 3 port valves, faulty sensors, burnt out compressor connections. Often something simple as having the correct setting will make a significant difference to a heat pump performance.