Interesting. According to http://www.house.gov/jct/x-60-05.pdf (page 82
of the pdf) a qualifying furnace (for the $150 tax break) has to be 95%
AFUE:

"A qualified natural gas, propane, or oil furnace or hot water boiler
is a natural gas,
propane, or oil furnace or hot water boiler with an annual fuel
utilization efficiency rate of at
least 95."

Now, Trane's top of the line Varaible 2-Stage furnace is 93% AFUE...
so, I'm not really sure if that is a realistic tax break right now for
current furnace technology. I don't know about water heaters. Who
knows, maybe there is someone out there that can benefit from this tax
credit.

Thanks for the idea though!