Smitty Two wrote:
In article ,
Winston wrote:

How about an extra decade or two? Is that worth 15 minutes a year?

Sure. Please cite a credible study showing that changing the anode
extends WH life by a decade or two.

A quick Google reveals nothing along those lines.

However, _Your Mobile Home: Energy and Repair Guide for Manufactured Housing
By John T. Krigger, Marty Lord, Bob Starkey_
states that a properly maintained tank should last
"at least 30 years". Note that they don't put
an upper limit on longevity.

I've never had to replace a hot water heater that I've
maintained.

What is the most popular failure mechanism for a
water heater? Leaks. How do leaks start?
When corrosion converts exposed portions of the
tank to oxide because the electrolytic protection
has failed.

If the electrolytic protection never fails, what
is to prevent a tank from lasting a very long
time?

--Winston