Do you know the model numbers of your furnace and heat pump? This will determine whether the equipment has 2-stages or not.

The model # shown on what I believe is the furnace manual is 355CAV. There is also a model # CNPVP6024ACAABAA on a tag on the outside of the furnace, and a model # 355CAV0600100 on a tag inside the front cover. The heat pump model # is 265ANH060-B. Thank You.

The 355CAV is a 3-stage furnace. I think this is equivalent to the Carrier 58MVC furnace that I have. This furnace can operate in low, medium, and high stages. There is no reason why it should only operate in the low stage with your Evolution thermostat. It sounds like the thermostat and/or the control board in the furnace has not been set up properly.

The heat pump is a single stage. This is the reason why it only runs with one fan speed setting. You have a 5 ton heat pump so it would make sense the fan is operating in the high stage.

You should find out what temperature is set for the heat pump lock out. I think the Evolution thermostat supports two lock out temperatures. One where only the heat pump operates, and the other when only the furnace operates. Between the two temperatures either can operate. The controller will first try to heat the house with the heat pump, and then turn on the furnace if it is taking too long. This is not going to work well if the furnace only operates with the low fan speed.

You have a very nice furnace and controller. It should be set up properly for optimum comfort and efficiency.