I am replacing an old AC unit with a heat pump. I have a high efficiency furnace that is only a few years old - specifically Trane model TU4100R9V4. There don't seem to be any heat pump/coil combinations out there that qualify for the tax credit using the existing furnace. Can anyone confirm this? Hopefully I've missed something... I have had several contractors give quotes, but there wasn't a consistent answer on the tax credit. Thanks for the help!