On Mon, 11 Feb 2008 04:23:57 GMT, Malcolm Hoar wrote:

The tank is "leaking" heat 24 hours per day, 7 days a week.
A well insulated tank will store the energy you used and
paid for. A poorly insulated tank will throw it away.

Another good point.

Does the Efficiency Factor take this heat leakage into account?
Or is the ONLY way to research the insulation thickness (which doesn't seem
to be on the energy star label).

What's the easiest way to compare heat leakage between two water heaters?

Donna