I have a duel fuel system with a 4 year old Lennox heat pump backed up by a 17 year old Carrier gas furnace. The gas furnace requires replacement. Would a single stage gas furnace be preferable to a two stage furnace considering heat pump primary/gas back up installation controlled by the Lennox Duel Fuel switch panel?

[Edited by dodger on 11-29-2005 at 06:13 PM]