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Water Heaters 101 > Choosing a Water Heater

What you'll find on this page: When it comes to buying a water heater, everybody wants a quick answer, but there just isn't one. However, there ARE ways of navigating the maze.

The Tough Question

Legions of people ask us every year to choose for them, and we won't do it. There IS no simple answer. No water heater is going to be right for everybody and each person has to figure out which is right on their own. But we can help you with that.

There are a kajillion models and model numbers change all the time. We don't even try to keep track of them all. What we can do, and what we try to do, is educate you about a subject that hardly anybody knows anything about and set your feet on the path to finding the right water heater for you.


Longevity and Efficiency

If you've read very much of our site, you'll likely know that we like to see people buy a water heater that has an exposed, hex-head, magnesium anode installed in it. That offers at least the chance of removing it for inspection without totally destroying it. It also leaves room in the hot port for what is known as a combo anode rod comprising an anode, hot-water outlet and dielectric PEX-lined steel nipple.

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If you were to buy a 12-year-warranty heater, likely the only difference between it and a 6-year-warranty one would be extra anodic metal: either a larger-diameter hex anode, or a normal one along with a half-length outlet rod in the hot port. We'd rather see you put a full-length rod there -- and save the premium you'd pay for the longer-warranty tank. And installing it just involves screwing it into the hot port.

We'd also want you to install a sediment flush kit comprising a curved dip tube and ball valve drain assembly if you live in a hard-water area, unless you're already using a water softener, which eliminates most mineral sediment buildup. Installing these parts may seem daunting, but we make it easier for you with our Know-How page. Oh, and by the way: if you install the flush kit, don't forget to use it once a year! Put it in your scheduler, if you use one. The time slips by faster than you think!


There has been much talk and a certain amount of e-mail to us regarding instantaneous water heaters, also known as tankless or point-of-use. If you install a well-insulated tank-type water heater, you can equal the efficiency of these latter for a great deal less cost and trouble. You'd think the instantaneous heaters would be more efficient, but it's not necessarily true. And they're expensive and finicky compared to the more common tank heaters. If you'd like to know more about our thinking on this, go to Tankless.

There are specific circumstances where this type of heater is the preferable choice, but in general, we suggest going with the simpler, easier-to-live-with, tank-type heater.


Needs and Comparisons

Who needs what? That is the question! There are ways to rate one water heater against another. But what does that mean relative to you? With fuel bills going up, any logical person simply wants "enough."

So before you read the rest of this page, here is a simple equation. First use a sizing program (see Resources) to determine what your particular needs are. Then, on the one hand, compare gallons, Btu input or KwH, first-hour recovery, insulation thickness (if you can) or Energy Factor. On the other hand, throw in our maintenance parameters: what metal is the anode made of? How thick is the anode? How many anodes in the heater? Is there room for a second? Do you have hard water, and thus, need a sediment flush kit? (People with water softeners can skip the flush kit unless their heater has an aluminum anode. Softeners eliminate mineral sediment, but the anode creates a different kind.) If some of this confuses you, buy a consultation and we'll steer you through it. If you then buy a product we suggest within 10 days, we'll refund the fee.


Other factors you're going to run into will include price, availability and installation options. The things we think are important may not be important to you. At minimum, you need to read Anodes, and Sediment, With that, you'll be well on your way to making a decision. But if you're in too big a hurry to do that research, don't expect us to hand the answer to you on a platter. It simply can't be done. If you don't know the language with which to frame the question, we won't be able to help you much because we'll be speaking that language to answer. And in the end, you, the buyer, still have to do some research. Otherwise, you should stand in front of a mirror and say, "You dummy! Look at the lousy water heater you chose for me!"


If you're replacing a water heater, the greater question is, "Did the old one work well enough?" Now if the answer is "no," a good many folks would think, "I have a 30-gallon, so I ought to buy a 40-gallon" or "I have a 40-gallon, so I ought to buy a 50-gallon." Don't think only in terms of gallonage. Think in terms of Btu input or first-hour recovery.

These terms involve how rapidly a tank can heat water. A boiler that can heat a whole apartment complex or skyscraper sometimes has no storage, only a series of copper tubes running through a very hot fire. The water is heated instantaneously. Some very powerful commercial water heaters have very little capacity. For instance, a 75,000 Btu, 100-gallon light commercial water heater is a good deal less potent than a 250,000 Btu, 65-gallon tank.

First-hour recovery essentially combines the hot water a tank can hold with what it can heat in one hour. Used in conjunction with the yellow federal energy sticker, it provides a means of comparing different tanks, along with the other things we've mentioned.


What Brand Lasts the Longest?

Everybody's. Nobody's. The vast majority of tank-type water heaters are all made in the same way, regardless of manufacturer. A ceramic coating is bonded to a steel tank. But it's an imperfect process and some heaters get a better coating than others. That's one reason why one tank will last a long time and one will last a short one.

Get a thousand plumbers together and some will say A.O. Smith is the best and Rheem is the worst. Others will say Rheem is the best and Smith is the worst. Everybody can't be right. What gives? Experiences. If one plumber gets more good Rheems and bad Smiths, or more good Smiths and bad Rheems, then he will get the idea that one is better than the other. Same with homeowners. It's a cinch that if your last tank lasted 20 years, you'll buy another like it and expect IT to last 20 more years. Might not happen.


On the other hand, if you maintain your heater as we advise here, it will last the longest no matter who made it -- unless it's defective from the start.

Tankless owners beware: if you have hard water, your units will need regular, expensive maintenance or their efficiency will drop rapidly and they'll probably fail altogether. This is a place where softened water will help you. It's hard on the anodes of tank-type heaters, but kind to heat exchangers in tankless heaters.

And one more thing: the brand that lasts the longest might be the Marathon, made by a subsidiary of Rheem. It has a plastic-lined tank and a lifetime guarantee. But it's also a lot more expensive than the others.


What Brand Is Most Reliable?

Everybody's. Nobody's. This one covers several facets. As we said above, they are all made the same way. That said, the federal government mandate of FVIR systems on gas heaters caused the makers enormous headaches and generated incredible bad will among buyers, who got stuck with heaters that broke and had to be replaced or were chronically troublesome. Those systems are NOT all the same, but the manufacturers have engineered past the worst of the problems, and we don't hear FVIR complaints so much any more.


It may be that some are less prone to shut down, or do it less often because of the size or position of their air screens. We do not have a complete handle on this, so we can't tell you definitively this is so. It's a big marketplace with millions of scenarios. Some people say Rheems are less prone to dust-caused shutdown. Bradford Whites may have a bigger air screen, and they were the first to offer a reset button, but now other brands have that, too. But get used to dusting your water heater if you want a hot shower.

Traditional electric water heaters don't have FVIR devices, but they do have electric elements and thermostats that fail eventually. This is function, as opposed to longevity, which is mostly glass lining and anodes. Don't confuse the two.


Beware of Complexity

We're getting into a time when some people are heavily promoting energy efficiency. Often that goes hand in hand with complexity. Complex water heaters have more problems than simple water heaters. About the only thing that can go wrong with the 37-year-old water heater in my garage is a bad thermocouple. It failed a few years ago. I now shower in complete tranquillity.

Power-vent heaters have controls and a fan that can fail. Heat-pump electric water heaters have an air filter that MUST be cleaned or the energy-saving heat pump stops working and you're back to a very expensive resistance-type heater. Condensing gas water heaters are super-efficient, but are power-vent by nature, and have an acid condensate that users ignore to their peril.


Odds are, you know more about your car than your water heater, even though the car is far more complex. There are answers to all your questions here, but you have to read a little to find them. Read, learn, and if the answer still eludes you, ask.

-- Randy Schuyler