On 2006-02-07, wrote:

None of the above:

http://www.askthebuilder.com/451_Tan...ng_Facts.shtml

That article is bogus. In doing the cost comparison, the author
assumes that the tankless gas water heater always uses gas at its peak
rate, which is false. A tankless gas water heater has a modulating
gas valve, and it will only use enough gas to provide the required
temperature rise. It is incontrovertible that all other things being
the same, a tankless heater without any standby losses will use less
energy than a tank heater with standby losses.

The author also complains that tankless water heaters provide a
constant temperature rise, so that the hot water is hotter in the
summer when the incoming cold water is hotter. While I believe some
older models do this, most current models will modulate the gas usage
to provide a constant output temperature as the input temperature
changes.

In other words, the article's two chief complaints are invalid.

Cheers, Wayne