I have a York Heat Pump Model N2AHD10A06,and Central Air unit. The heating system is still keeping the house at the desired temperature (68 degrees) however it runs nonstop and the emergency heat light stays on also. Have not received my electric bill so I'm not sure if it is eating power or not. What need to done or replaced?

There are many items that can cause the type of problems you are having but most of them require low voltage circuit knowledge and a set of guages with license from the EPA to use. Unless you are authorised to tap into the refrigerant system you cannot tell if the heat pump is having a problem or if the problem is elsewhere.

The running nonstop could also be caused by the weather being cold and taxing the heat pump to its maximum output. I suggest calling for ON Site professional service from one of your local HVAC company's to determine what the problem is before your utility bill skyrocket.

I am sure you keep your furnace filter clean and the return air open and not restricted. I am also sure you have all the registers open fully. These are the only items that you can actually check unless you have knowledge of heat pump systems and the tools to work on them.