I have a 25 y/o unit, one part of furnace in the attic and a outside unit all electric
The outside says magic chef
The old thermostat is a honeywell with the following wiring:

Wire color ----------position
Green G
Red RC also jumpers to RH
Red W2
White W1
Yellow Y1

New digital thermostat is Huntermodel 42999B
It accepts five wires
Positions available are:
G
W
Y
RH
RC
My question is where does the 2nd red wire going to W2 hook up to? And why does the old RC jumper to Rh I figured I wouldn't need the jumper with a five wire system
Thanks for any and all help

The Rh and Rc are jumper because you have only one 24 volt thermostat. R means 24 v supply the c means cool and the h means heat so you must have AC. The W2 is a heat pump relay 2. I am not 110% sure but I think you bought a non-compatible stat. Check out these specs model 42999B digital thermostats at hunter-thermostats.com. I don't see that this unit can handle a heat pump.