I just had a Trane XV95 two stage furnace installed together with a new Honeywell RTH8500 thermostat. This is a stand alone system. There is no central air. The thermostat was wired for two stages of heat, wires on W and W2. I am a bit confused about the programming of the thermostat. For system type (function 170) there is an option for Gas heat without central air, but this option does not mention two stages. There are options for multiple stages but they involve both heat and cool and I don't have cool. Called Honeywell twice, and got contradictory responses as to what option I should choose. Can anyone help me resolve this programming issue? I have experimented with both options and to complicate matters it seems as if only one stage of the furnace is operating, but I can't really tell if it is the first or second stage. What controls the operation of the stages, and is there a way to tell which of the two stages is energized? Thanks ahead of time for provided information.