On Sat, 07 Nov 2009 10:36:17 -0800, JRStern
wrote:

I see Home Depot has a line of GE/Rheem gas water heaters:

* 40 gallon, 6 year warranty, $488
* 38 gallon, 9 year warranty, self-cleaning, $498
* 40 gallon, 12 year warranty, self-cleaning, $578

My question is, what does this self-cleaning mean, and is it likely
that the extra bucks for the 12-year is a good investment?

In Southern Arizona, our water contains a high degree of "gypsum".
Leave a glass of water out overnight,
and there's a white sediment on the bottom.

In water heaters, this builds up to a "paste"
that can't be flushed out using the water heater drain.
In time, the water heater must be replaced.

A heater with a "swirl" would lift the sediment
so it'd go out with the hot water.