Rule of thumb,replace the darn thing one year before the Warranty expires if you have hard or acidic water. The only way these things last is by doing a complete draining once a year.

Learned the hard way,45k in damage from a nine year Heater that roman candled in year eight. And yes,we did drain our heater once a year.

I’m switching to an on-demand system. Fewer worries then. I’ve had one blow it’s top and cause some water damage but nothing near your experience. Yikes!

Water hardness, sediment in the water, and the volume of water going through the heater.

Age comes in to play if there's some kind of corrosion issue like a bimetallic contact (pipes of differing metals coming in contact, which no knowledgeable plumber would install).

I'd say 12-15 years is about normal. If you're in a situation where it can leak and cause a lot of damage (like an upstairs condo) it's better to get ahead of it.

Just replaced both heating elements in my water heater. I have very hard water but, I put in a water softener a few years ago. It's very easy to replace the elements. The hardest part for me was draining the water from the water heater. It took about 3 hours to drain. 30 minutes to replace elements and thermostats. If you do anything with your water heater. TURN OFF THE POWER FIRST.

My experience has been that they last 10 to 15 years. I think hard water might cause them to fail sooner. It causes deposits on the heating elements of an electric water heater or tubes in a gas one. I used to flush mine out every few years by turning off the gas or electricity and connecting a hose run to the outside. I open the bottom drain valve and let it run for a minute or two. I would see a lot of brown crud when the first water came out.

I don't know if usage affects life but I would think more usage would cause wear of the glass lining on the tank. This site says it makes a big difference.

https://www.nachi.org/lifespan-water-heater.htm

useage would make a difference, yes. (and of course it would be possible for one person to use it as much as 2 or three if they were washing laundry with lots of hot water, bathing more often, etc)

This may be one of the questions I never had to answer in my plumbing career.

What generally kills a water heater is hard water. Deposits build up on the sides of the tank and on the elements. When the deposits cover the elements, they burn out because they don't have water to cool the element and they literally melt into. Even without the sediment, the elements wear out like just like light bulbs or stove elements. More people in the house would cause the elements to burn out faster, for the same reason, it would also shorten the life of the tank, but I don't think substantially.

When elements burn out, they can be replaced. The cost to replace the elements will probably be about 25% of the cost to replace the whole unit. When the tank fails the heater is DOA. Tanks usually fail slowly, which is very good; they will usually develop what we call pin-holes, or sand-holes and may fail with a drip, a fine mist, or steam.

To give you a straight answer to your question, it is my opinion that all other things being equal, that a water heater will last longer with less usage.

As far as guesswork as to how long you should expect a water heater to last, it would take a crystal ball. I have worked on water heaters that were 40 years old, and I have seen them fail after a few months of usage. Generally they will last ten to fifteen years. Interestingly, I have never seen a difference in really expensive brands and lesser expensive brands. When you buy a water heater, buy based on the energy ratings alone.

I hope that helps.

My water heater is approaching 10 years old. I live in an area with very soft water and I have lived alone the whole time. I recall having a problem with it early on, and it was fixed under a the warranty. Other than that I have had no maintenance done on it and, so far, so good.

Now I am having new pipes installed and am wondering if I should ask the plumbers doing the work to check out my water heater. Any advice on that?

Thanks so much for giving me the benefit of your expertise!

Your plumber can look for leaks, look for surface rust, but he cant tell what kind of shape the inside is in without opening it up, and personally, if I weren't having a problem, I would save it until I did. If you have really soft water, you could get a lot of usage out of your water heater. About the only routine maintenance is to open one up and scrape out the sediment that is rarely worth the effort. (I have never done it on my heater.) If you have soft water you won't have any significant sediment. You might have him check to see that your T&P valve (emergency Temperature and Pressure relief valve) is working and that the line is clear, that takes about ten seconds. Cross your fingers, maybe you can go ten more years!

If he tells you, "Oh My God, this is ten years old, you have to replace it!" smile and tell him, "maybe later."

That’s exactly what I wanted to hear. If it ain’t broke...

They don't want any water heater more than 10 years old according to the agent. We do have a leak sensor so if it failed that way - which is what would damage the house - we'd get a warning.

We have moderately hard water - comes out of a limestone aquifer - and have never done the yearly drainage the manual recommended. So Thursday we're getting a new heat pump water heater. I wanted another solar one, but the closest installation company is over three hundred miles away in any direction. Not paying for the travel and overnight stays that would involve!

In my old house, which we had for thirty five + years the original water heater never failed. The pipes to it did, rotted the floor underneath and the water heater dropped through it. Even then the water heater was still working! We'd already made a deal to get rid of the house so the new owners had to fix it.

The anode rod slows down corrosion and rusting in the tank. It's dirt cheap, and easily replaceable. Regular anode rod replacements will extend the life of your water heater substantially.

Our water heater is 30+ years old and still cranking out the heat.

Thank you.