Flushing Out 15 Year Old Water Heater

So, for the first couple years after I moved in new house, I flushed (drained) the water heater once a year (its a gas unit). Then got busy and forgot. It been about 10 years since I last flushed and heater is still fine. On city water, so water is filtered pretty well. Was going to flush but then saw episode on This Old House, where new owner's flushed heater and two months later it failed (i.e. leaked). Plumber stated that his experience was that flushing a heater that hadn't been periodically flushed, always seem to result in failure soon after. Not sure reason, whether ten years or crude in the bottom covered cracks in liner and once buildup was removed, crack was exposed resulting in failure soon after.... No clue.

Curious what the experienced plumbers on this web-site think of this guy's theory/experience.....

There might be something to that, I can't say for sure. I can say that a 15 year old water heater has got to be about ready for the retirement home. You could try flushing and see what happens. On other hand, if it's working fine as it is, what is there to gain by flushing it at this point? If it was mine, I'd leave well enough alone but watch it closely for signs of leaking, and I would certainly budget for a new heater in the near future.

heater

If there is any truth to that saying, then it may be because the material is deteriorating the heater's shell, and when it is removed, the thinner areas are exposed to the water and that can hasten the final rusting process.