Granted that the 80% is less than the 92% units. But the **WEIGHTED**
average stack temperature is much less than the older versions. Every
short fire of the gas starts with the heat exchanger at ambient plus no
more than a couple of degrees. Stack doesn't even get warm to the touch
for half of the burn time in moderate weather. Hard to argue with that.

This also argues to the point that a temperature setback may not produce
the fuel savings one might expect.

Stormin Mormon wrote:
80% are hardly known for "sucking every BTU".