Just bought a house with a »Ruud electrioc furnace and heat pump, on the thermostat I read Heat and EM Heat. What should it be set to?

If it's wired right for 2 stage, selecting heat mode will run the outdoor heat pump at all times. 2nd stage electric coils comes on as auxillry heat when the outside unit is in defrost mode or can't keep up by more than 3 degrees. Emergency heat should only be used to cut off power to outside unit if it has problem running.

The electric coils are in the inside furnace/ air handler by the way