how long do electric water heater elements last?

Are they supposed to be changed preemptively after so many years, but before they fail?

Reply to
taxed and spent
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No, they last 10 or 20 years or more and there's no reason to replace them early.

It's also not true that the water heater will always have a lot of crud in it. I mistakenly replaced mine after about 10 years, and I cut it open and there was just about 2 tablespoonsful of crud. It would have taken more than 300 years to reach the element.

What you should know is that when the time comes, you don't have to drain the tank to replace even the lower element. Turn OFF the electricity to the WH. Turn OFF the water going to the WH, turn ON the hot water somewhere until no more water comes out. Then unbolt or unscrew the element, pull it out and lickety-split put the new one back in and start screwing it (or the screws) in. When I did that I spilled only about a tablespoon of water into insulation just inside the outer cover. It evaporated eventually.

Saved all the hot water, and a bunch of time that it takes to drain the tank and refill it. .

Reply to
micky

One at our cabin(well water) was put in '97. I had to replace top side thermostat few years ago. Still working good. Having two element(top and bottom) I'd think replacing element is not rush job.

Reply to
Tony Hwang

It depends on he water PH. I once lived in a house with well water that was very acidic. It actually ate copper pipes, and water heater elements had to be replaced every 3 or 4 years.

I worked for a guy who lived in a town that had very high calcium in the water. In 3 years, his water heater was half filled with lime particles. The lower element was buried in it. I tried to flush out all the lime, but it was not possible. That 3 year old water heater had to be replaced. Everyone in that town has that problem.

So, this question has no answer.....

Reply to
Jerry.Tan

You're right. I guess I meant in absence of history or neighbors sayin that WH wear out soon, he shouldn't assume it will happen soon.

And since they sell elements many places and it doesn't take more than an hour to put one in, there's no rush.

Reply to
micky

Except this is a vacation rental, and when it goes out when a tenant is there and not the owner, a plumber is called. :(

Reply to
taxed and spent

I read some where that if you crank out the drain valve from the WH, and put in a full flow ball valve, you can drain a lot more crud than what the angle valve (provided) does.

Reply to
Stormin Mormon

That's at most only if there is crud to drain out. Mine had hardly any.

There have been a lot of posts over the years about that valve.

Reply to
micky

Interesting procedure. I'm surprised that it works. The hole in the tank for the element is large and I would think even without a way for air to enter at the top, water would still come pouring out. And if for some reason you can't get the new one in, I guess you better be prepared for the consequences. And the "saved all the hot water" part sounds positively dangerous.

Reply to
trader_4

In my experience their life is highly variable. I've had them burn out in a couple years and I've had them last 20 years. One thing that seems to make them burn out faster is that the bottom ones wind up down in the muck at the bottom of the tank and that shortens their life.

speaking of muck, I've had far far less muck form by turning the temperature down below "normal" on the dial. I keep it around 120 degrees or less and it seems to reduce the formation of muck and crud. When I used to run them hot they would build up muck all the way up to teh bottom element (and make it burn out) in only a few years. I almost couldn't get one of the elements out it was so encased in calcium buildup.

Reply to
Ashton Crusher

It's the type I had and the type I cut open. I forget what the swirling is supposed to do. ???

Because there has been no detectable crud in the water that comes out of the sink that I touch with my hands, and if there were crud in the bath water, I think I'd notice it. That just leaves the washing machine where i probably would not notce it. The garden hose where I would not notice it, but I don't use very often). And the aerators, which have never clogged or slowed. If there crud in the water it would be in all the outputs, not just the garden hose.

**It's probably the type I have now, since I bought the new one from the same place, in orde to get the inlet and outlet pipes in the same place I'm somewhat compulsive and didn't want any Z or flexible connections.
Reply to
micky

The lower elements tend to have shorter lives than the upper element. When one goes, there is a difference, but some hot water is still available. It will take longer to heat.

Reply to
John G

Less than 120 is a good range for legionella though. I opt for 130 for safety.

Reply to
Ed Pawlowski

NIH has some differing views but you can find lots of others:

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That's 77F to 107.6F with an optimal growth temperature of 95F.

Legionella pneumophila (203). Legionellae are intracellular parasites of freshwater protozoa and use a similar mechanism to multiply within mammalian cells (91). These bacteria cause respiratory disease in humans when a susceptible host inhales aerosolized water containing the bacteria or aspirates water containing the bacteria.>> Again:

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The key to infection is "inhaling aersolized" water or actually aspirating water into the lungs. My understanding is that it grows best in the condensate of rooftoop cooling towers and not in water heaters:

One of the reasons it thrives in cooling towers is that it prefers warm, stagnant water with a source of food. A cooling tower is pretty much the ideal growth medium because bugs, bird droppings and all sorts of nasty food for bacteria live there. The first diagnosed outbreak that gave the bug its name was found in the Legionnaire's hotel cooling tower.

Those most likely at risk probably should amp up the temperature of their water heater: a.. Organ transplants (kidney, heart, etc.) b.. Age (older persons are more likely to get disease) c.. Heavy smoking d.. Weakened immune system (cancer patients, HIV-infected individuals) e.. Underlying medical problem (respiratory disease, diabetes, cancer, renal dialysis, etc.) f.. Certain drug therapies (corticosteroids) g.. Heavy consumption of alcoholic beverages Since I am not in the high risk category and the water in my 120F water heater doesn't have much of a chance to get stagnant, I don't worry about it. Too much. Many other nastier demons out there.

Here's something really nasty that can be found in warm freshwater.

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As for scalding v. Legionnaire's, there are apparently 10K to 50K cases a year of LD compared to 500K for scaldings. That makes the risk from hot water burns far more likely than catching Legionnaire's. I think the increased longevity of the heater and the lessening of the scald risk are well worth turning the dial back. Saves money, too. YMMV

Over 500,000 scald burns occur annually in the United States. The two highest risk populations are children under the age of 5 and adults over 65.

Did you know?

a.. Hot liquids can cause life-threatening burn injuries. b.. Scalds are the number-one cause of burn injury to children under age

  1. c.. Burn accidents frequently occur when parents or caregivers are in a hurry, angry, or under a lot of pressure. d.. Coffee, tea, soup and hot tap water can be hot enough to cause serious burn injury. e.. Scald and steam burns are often associated with microwave oven use. * f.. When tap water reaches 140? F, it can cause a third degree (full thickness) burn in just five seconds. g.. Hot tap water accounts for 17% of all childhood scald hospitalizations.
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*Ever heat water in a coffee mug and have it boil over just as you open the door? It's very nasty and I assume that it's the same sort of phenomenon where water can freeze over in seconds if it's supercooled and it's disturbed by a loud noise.

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Reply to
Robert Green

I haven't taken mine apart but it's outlived its predecessor which used to run at 140F (I keep mine at 120F coming out of the tap - eventually - but it takes a while to get there.) We'll see when this one dies. I also trimmed the cold water input to the tank to try to limit the thermal shock of 36F water (the lowest I've ever measured) hitting 120F internals.

What I haven't come across yet (still looking) is something on the web that explains how water heaters build up so much sediment. The "duh" answer is of course, sedimentation but it seems to be more complex than that otherwise there would be sediment filtration on the incoming cold water line.

You would also think that heating the water causes more sediment to dissolve so I am not sure exactly what most causes gunk buildup. I suspect it's the quality of the water, but I haven't seen any study that apportions the causes of sedimentation.

Reply to
Robert Green

The stuff that accumulates in the water heater is dissolved calcium in the water. YMMV depending on what is in the water to start with. When I was in the north east our water was very good and water heaters lasted forever. Here in Florida, they don't last that long. Ten years is typical.

Reply to
gfretwell

They last about as long as the anode rods do, or roughly 6-10 years. So if you change the anode(s) about every 6 years, you should get about 20 years from the heating elements. There are lifetime warranted elements and also elements that won't burn out if you accidentally turn on the electricity before the heater is completely full of water.

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has info about all this.

Reply to
larrymoencurly

Yes, you would think heating it would make it dissolve stuff, not precipitate it but perhaps the fact that it just sits there perking away (figuratively) much of the day with no water movement somehow results in precipitates dropping out. Or perhaps the mixing of cold and hot water causes precipitation regardless of it being on average quite hot and lessening the high temp results in less of that presumed effect.

Reply to
Ashton Crusher

Well, I'll keep looking. What's clear is that gunk DOES build up and with some heaters/areas it builds up pretty quickly. It would be nice if lowering the temperature not only saved money, but lengthened the service life of the heater. We'll get at least one more data point when mine finally goes. I started seeing some water dripping lately. Maybe I'll find out soon. )-:

Reply to
Robert Green

Bear that in mind, Taxed.

Reply to
micky

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