I have a Rheem heat pump with auxillary and emergency heat. My current thermostat is a Seco TA-2000 with the following wiring configuration: B W2 X R G and a piece of wire connected between E and W2. There's also an orange wire that's not connected to the thermostat. The Honeywell manual does not address this situation beyond refering me to a heating / cooling contractor. My terminals on the Honeywell thermostat are as follows:
E Aux Y G O L R B C. Can anyone tell me the correct wiring configuration? Thanks.

hvac1000

Have you looked under the sticky notes at the top of the page. Might be something in there about the letter/color change