Duo Therm wiring for new digital thermostat

[dezbull]

I am wanting to upgrade this Duo Therm rsv420k62 thermostat to a digital Honeywell RTH8580WF.

The basic thermostat color codes pic may define all of my wires in the Duo Therm pic except for the black wire labeled as H.

I came across the manual for this thermostat, and I believe the H black wire is for high fan or is it?

The RH and W are for the furnace.

How do I hook all of my wires to a Honeywell RTH8580WF thermostat?

[Isaac-1]

Don't expect the Duo-Therm to use conventional wire color codes, I wish I could help more, I upgraded my DuoTherm analog thermostat to a modern Honeywell battery powered unit last year.  Unfortunately yours appears to be even older than my old DuoTherm analog and may use different voltages.  As I recall mine used a 7.5V electrical system, not 24V like traditional home units.

p.s. the extra wire may be the hi/low fan speed control

[Super8mm]

I am wanting to upgrade this Duo Therm rsv420k62 thermostat to a digital Honeywell RTH8580WF.
The basic thermostat color codes pic may define all of my wires in the Duo Therm pic except for the black wire labeled as H.
I came across the manual for this thermostat, and I believe the H black wire is for high fan or is it?
The RH and W are for the furnace.
How do I hook all of my wires to a Honeywell RTH8580WF thermostat?

See if  this might help?
http://www.atwoodmobile.com/manuals/furnaces/MPD%2032046%20E%2011.27.06.pdf