I am trying to replace the thermostat for my heat pump the one I've got seems to be running the emergency heat only. All wires were connected as they were in the old one. Is regular heat and emergency heat considered multi-stage? If so, I need another thermostat... please advise.

is a heat pump with emergency heat a multi stage heat pump



No a multi stage heat pump has 2 or more compressors in it. You probably have 2 stage heat which is first stage heat pump and second stage regular resistance heat. This is the standard setup.