Not very compelling, unfortunately.
I've used some pretty old gas water heaters and their gas use wasn't that much different than what I've seen in new units.
Of course not, you're an opinionated homeowner that thinks your personal experience is the rule of thumb for many, which leads down to maybe a couple of water heater experiences which I deal with weekly.
Should I or anyone trust your opinion at this point given your limited point of view on such matters of information trading? I think not.
I love people who doubt logic, first hand experiences with product knowledge. I'm no different than any other plumber on this site but I have no problem being the most descriptive to the nonsense that was thrown on this thread.
Am I expected to discount my firsthand experiences of weekly water heater replacements to listen to a couple homeowners speaking from solo experiences, cherishing the fact you have dinosaurs in the basement still producing hot water without a "known" cost to you because you can't gauge against a new one?
I replace a lot of water heaters around the 5 to 9 year mark quite often. 99% of them were never touched since the day they were installed.
What does that mean, intelligent homeowners? That means the heater never was drained, never removed of sediment, never had an anode rod replaced inside the water heater when the rod substantially started to lose its ability to protect the steel tank. Do you all comprehend this well known fact about water heaters?
Secondly, hard water and high water pressure also has deciding factors about these water heaters. That constant flexing of mild steel in water heater tanks allows for the paper thin glass lining to pop off the inside of the tank walls, exposing bare steel to be in direct contact with water. We know where this leads.
The constant "flexing" of the tank between pressure variations creates microscopic cracks in the steel tank that start an ongoing process of leaks that can close themselves back up, calcify shut. If you could cleanly strip an older water heater apart and see how many other points of failure has before the big one that leaks rears its ugly head, you'd see that the tank's condition was poor before the final leak arrived.
I've seen burners that were completely covered with carbon buildup, scaling of the flue walls inside the heater or even further up the exhaust system that contributed to the demise of the tank's efficiency.
People change their tv's almost every 5 years these days
Their phones
Their cars
IF, people could visually and financially see how inefficient a water heater becomes by viewing the condition inside the tank, they'd replace them more often.
The penny-pinchers would see the issue and instantly understand that there's no way that unit is producing the efficiency as it once had when initially bought.
Yahoo just posted a link about now they are going after appliances, cash for fridges. I have a 24 year old freezer that still keeps food frozen, but there's no way in hell it is efficient like the day it was installed.
The gaskets are wore out on the lid, the coils have probably never been cleaned (like the majority) and after that many years, you cannot expect anything of the nature to be cost efficient product.
It's the attitude of "it still runs it's fine" attitude that creates a glutton of extra expense not visually seen in the electric or gas bill. It's there, but until you know the costs incurred, for many it just simply does not exist.
I wonder why every water heater I pull out weighs 20 to 70 pounds more than what it weighed when it was first installed.
Oh I don't know, maybe I'm a plumber and have the back pains and hemmorhoids to prove it?
Continue with the circling of the wagons, it's not getting anywhere but debunked.
The majority put-it-in-and-forget-it with water heaters. Job security for me because the homeowner isn't educated enough to understand that the water heater is always the lowest point of the potable water system inside the structure. It's a given that it's going to be the collector of everything brought in from the public or private water supply. Every single water heater made today is a water heater with a boiler drain attached to the sidewall, not the bottom of the tank which indirectly seals the fate of that water heater given the fact that sediment, once entering that unit will never leave it.
It's a fact that my rhetoric on these subject matters will be used as resource links for understanding plumbing systems and situations across the globe. The information I put out there coincides with manufacture's recommendations and product knowledge
reality.