Can someone answer what the w3 wire would need to be hook to on the new Honeywell RTH7400 5-1-1. we are removing a addison thermostat which runs a Gas furnace and a heatpump. Please help with wiring diagram

Have you read the installers guide that came with your stat?

Yes we have read it there is No mention of a w3 wire and what it connects to

What is it attached to on your furnace?

Not sure I will try to trace it back tomorrow and get back to you.