I have a Nordyne Heater,A/C, mod # E2EB-020HA, Miller inside coil mod #C3QA-042U-B, outside unit Nordyne, mod # S3QA-042KA. I want to know if the heater part of this unit, can be completely disconnected, so the a/c is the only part of the unit is working. If it can be done, how do I do this. I have over 8 years experience as a commercial electrician, but do not have much experience on heating and air condition. Thanks for any help.

I see no reason why the electric heater unit could not be disconnected. Most of these types of appliances have some type of wiring diagram on them somewhere inside the cabinet. Check it out and just disconnect the electric heater, Make sure that any wires that connect the heater are well isolated and insulated after disconnecting.

Just disconnect the 24 volt power wire to the sequencer. That will prevent the heater from working.