Does anyone know the difference in eheat and heat on a carrier thermostat?

This thermostat is used with a heat pump. A heat pump is an air conditioner that works with a reversing valve and electric heating strips. The valve makes the inside coils heat instead of cool and the heating strips work with the coil to help warm the air when the temperature is too cool outside to extract the heat from the outside air. When the outside unit is not working properly you can switch the thermostat into E-heat mode which turns off the outside unit and energizes the electric heating coils only. This will however run up the electric bill because you are using the electric heating elements only. When it is set in the heat mode you will use a mix of the outside unit and supplemental heating coils.

The filter indicator is just a reminder to change the air filter on a regular basis. It usually determines how many hours the air handler has run and on that time frame it turns on the reminder on every 100 hours or so. You are supposed to change the filter then press the reset button for it to remind you to change the filter after the predetermined time.

E heat = electric furnace

heat = gas furnace

change filter is typically on a timer, it usually doesnt sense your filters cleanliness. Read the instruction manual and I recommend changing your filter every 30 days.

What Is Eheat