i have a problem with the 8570 stat. when the dip switches are configured for h/p operation, y is not energized in heat, only w2... changed stat, same thing. you guys ever see this before?
In the land of the blind the one eyed man is King! semper fi
I am not familiar with this thermostat, but some multi-use thermostats require a y1 to w1 jumper for heat pump operation.