+ There are three types: traditional tank, tankless, and calorifiers.
+ The first is the cheapest, in the short term. But they only last for 13 years at the best. Mine, ITOT, is a six year version and takes $1000 in parts and labor to replace, without complications.
- the complication, of course, is that when they installed it they had to take out and reinstall a couple of doors, so we'd have to do the same to replace it, so add another $1000.
+ For that amount of money you can install a tankLESS unit, prolly two of them. If you are smart.
- As it is, since my predecessor was not, I can do that, but then what to do with the old unit?
I vote for kicking it into a corner and letting the next owner decide if s/he wants to go to the expense of ripping out and replacing doors to get rid of it.
+ The third is appealing in an engineering sense and is what I have on the boat. A calorifier that takes hot space heating water from the furnace and circulates it through a tank to heat the service water. But new technology to American plumbers. And still leaves me with the problem of what to do with the old heater...
So how to avoid this angst?
Start with a healthy dose of RTFM:
+ ITOT tank heaters have anodes to counter-effect water chemistry. The anodes are designed to be replaced periodically, like every year. We, of course, have never touched them.
+ They also have drains and are designed to be flushed out every six months preferably, but at least annually. Again, we, of course, have never done this.
Had I done these things, maybe it would have lasted longer.
Does anyone remember Marley?
But in any case, you can check the manufacturer date with the serial number:
ITOT there are very few true manufacturers, and AO Smith is a big one. Mine was State Industries, subsequently acquired by AO Smith.
So check out the date of your unit and get prepared, either by saving up or at least having a plumber come by and check things out.
Clearly, after all this, the TANK solution is off my 'scope. Haven't yet decide between options #2 and #3.
But for you, my friends, as with my cancer bouts (get your colonscopies and stay out of the sun), I hope this little Screwtape venture may spare you further misery.
Check your anodes, purge the tank. Every six months.