My hat pump only works on emergency heat - Heating & Cooling

Stays on because it can not satisfy the tstat or continues to heat past set point

Your question makes no sense. You dont have a heat pump with ONLY emergency heat. Is it working or not???

Your thermostat should have an emergency heat setting. Putting the thermostat in that position should make the electric heat strips only work and keep the compressor from coming on. If your thermostat doesn't have an emergency heat selection disconnect the compressor outside at the power source. Turn the thermostat 5 degrees Above the Rim temperature the electric heat strips should come on.

No theirs no danger in running the Emergency Heat all the time, Emergency Heat is your backup heat mode. when the Heat Pump is not working do to a malfunction or Defrost, the Emergency Heat kicks in. The Emergency Heat is usually electric heaters so your electric bill will be much higher.

It's possible the "brain" thinks it can still supply some heat. Other wise there is a wiring problem or thermostat switch problem. Installed recently? Never used emergency heat before? What is your emergency heat type, gas or electric? Are you sure they are working. If not the "brain" senses and uses the only source available: heat pump. Thermostat? probably Honeywell? If so call Mfg customer service. Warranty on thermostat or heat pump? If so call customer service. Call your installer.

If you have an air to air heat pump, in colder temperatures, the heat pump will not heat as well as it would in warmer outdoor temperatures making it run longer. the digital thermostats work off of a built in algorithm that kicks on the auxiliary heat when the heat pump runs to long so that it will satisfy the thermostat quicker. This can be tied to the Emergency heat @ the thermostat energizing a few heating elements, or just energizing a separate element from the emergency heat. I always recommend on an air to air heat pump to run the emergency heat when you have consistent Outdoor temperatures below 20 degrees F because you will cycle the heat less by getting hotter heat making life more comfortable, and it costs about the same as running the heat pump since @ those temperatures, it will run all the time.

your unit is likely equipped with an outside temperature sensor that switches the heat pump to emergency heat when the outside temperature is too low for the heat pump to work efficiently. This is common

You mean you are using the Emergency heat setting instead of the heat pump????...You're using Natural gas only now tn emergency heat????That's fine...I wouldn't replace a heat pump if you have Natural gas....it's too expensive compared to Gas....you may be able to still use the heat pump as an Air Conditioner only , it depends on what's wrong with it...otherwise you will have to get a Central Air unit instead...cheaper and just use the Gas for heat

It stands for Emergency Heat. (Back up heat) . Normally you will find it on heat pumps. It's used manually when the compressor goes out on a heat pump. It's used automatically by the unit when it's so cold outside the heat pump can't keep up. This happens when there is not enough heat in the air to draw heat from. This happens at around 23 degrees. I hope this explains what emergency heat is and what it's used for.

Economy Mode = EM
Auxelary Mode = AUX
in em mode heat pump does most of the work in aux either an electric heating element is used or gas depending on if it is gas or all electric