O.K…the author admits it. He’s been derelict (AWOL) in feeding his article stash. Part of the reason (I know, ‘no excuses soldier!’) was a lull in the author’s topics of interest colliding with his consciousness…, fishing and kayaking suffered not. “A Conundrum”, is this Pipe’s first of 3 installments involving domestic water heaters of/for the future. Your Rip Van Winkle-esk author hopes he can make up for his last spell of laziness? by sparing the reader (in the future) a lot of “head scratching” when ‘must-choosing’ one of 3 sanctioned, electrically powered water heater designs.
Why would someone be put in this situation of ‘must choosing a water heater? Read on…
Of late, there was ‘zilch’ in the plumbing realm sufficiently inspiring Pete to nudge you. (He trusts the reader put the same time to good use?) However/But, the author DID do some wrestling-on-the-couch: “…..would it behoove the reader to know about some ‘plumbing things’ (politics included) that might prove, in the not-too-distant future, a possible lifestyle ‘upend-er’ for many. This change (the author believes) will involve HOT water. And, how the cold water turns into hot water might interest the reader.
Is your fresh water supply heated by using electricity or by burning natural gas or propane? This question is the seed of Pete’s story. (“Oil-ers’ are excused from class.)
Because climate change is forcing human activities to become as *environmentally clean as we can do them, staying clean via hot water (using some form of heat energy) will not escape closer and closer inspection.
The Big 3
Today, three concerns of geo conservationists are causing elected officials to fret over continued use of fuel gas (Natural Gas and Liquid Petroleum Gas (Propane) to fuel stoves. Concern 1. Radiation in Natural Gas includes uranium and thorium. 2. Stanford University researchers discovered using gas stoves raises indoor levels of the carcinogen benzene to higher levels than secondhand tobacco smoke.
3. Global Warming concerns include methane (mother of natural gas) leakage in the oil & gas exploration and production. And, additional concerns involve air-pollution, possible asphyxiation and fires.
Presently gas stoves are the ‘hot’ target. (Yes. That was a pun.). But, the author thinks gas water heaters and furnaces won’t be that far behind. He expects only a grace period (once stoves have been banned) before we see legislation aimed at them.
Hot Nuts and Bolts
Because the topic of hot water heaters can encompass so many technical aspects, the author wants to narrow his focus to the why of this article: There’s a chance that in the future, in enough parts of the Country, Natural Gas (due to health concerns) (and a little politics) will be phased out and *electricity will be tasked with making/facilitating all the domestic hot water. Those readers presently being served hot water made with electricity will not be affected. Those making hot water by Natural Gas/Propane will have to purchase a new, electric water heater. Of course those readers who use oil/kerosene will not be affected.
*Suburban dwellers relying on well pumps still need electricity (whether it be by solar or Utility), to live ‘on solar’.
Pete the Plumber would now (in 3 Installments) like to describe and illustrate 3 popular designs of electric holding tank water heaters on the American market, today, and tell you their advantages and shortcomings. The author did not include “tankless” water heaters in this discussion because he admit-tingly has a bias, born of decades of experience. He is not a fan.
Pete perceives 3 possible/probable ‘camps’ of questioning among the readership for this article on holding tank electric water heaters.
Camp 1. Bored-to-curious. Moot.
Camp 2. Individuals needing to replace an existing mass-produced water heater. (This could mean replacing a simple electric heater with another like it, OR replacing a gas water heater with an electric one.)
Camp 3. Individuals interested in 2 higher technological choices for a holding tank electric water heater either for replacement or new construction. *
*Pete thinks this new construction will be the arena where the political battles of banning the use of gas home appliances will find eventual traction.
O.K. Assuming the worst. Let’s say (in the future) one or more of my readers were informed that they need a new water heater. And…the County has successfully banned all new gas appliances. What would then go into the decision to choose an electric water heater?
Those readers presently served by an electrically heated hot water appliance wouldn’t feel the crush like the ‘gas-ers’ will, when/whenever fossil fuel hook-ups are banned for all new construction. And with a possible quick sunset on existing installations. Today’s basic tech level, mass produced holding tank electric water heaters could simply replace a worn out one. For an unfortunate “gas’er” how and what their choices are, are thoroughly discussed in the trio.
Yours truly was raised in homes with natural gas stoves and furnaces. He and wife, Katherine, also raised four children in a house with a gas stove and gas furnace. As a result, the author prefers gas cooking appliances over electric ones but understands the rationale for retiring the ‘blue flame’.
In some parts of the Country (especially mountainous and/or remote), fuel oil/kerosene can figure into the equation. Which energy gives the reader hot water? Yours truly has loved ones living in the ‘far flung’ whose homes and fresh water are heated by appliances burning fuel oil. This article will not discuss the merits or de-merits of fuel oil.
For all dwellers presently living in communities served by NG gas, with a future total ban successfully implemented, those hot showers the reader is presently enjoying are going to have to originate in an electrical or solar water heating appliance. This spells considerable expense, and the author hopes this article will aid them in choosing the ‘right’ hot water servant for their needs and budget.
The number of ‘gas’ holding tank water heaters versus the number of electric holding tank water heaters manufactured today (2023) is approximately 50/50.
There are three major American water heater manufacturers: A.O. Smith; Bradford White; and Rheem. Between these majors and a few independents there are hundreds of different brand names on the market. It’s not unlike the food canning business. One cannery might produce the same can of peaches with twenty different labels.
As mentioned above many readers may be employing “oil” for heating needs, both water and space. The author has a friend, Becky B., living in a mountainous location in his State who cooks with electricity, heats water with an oil-fired water heater and space heats with propane. Sometimes when living in extreme weather locations where electrical utilities routinely suffer outages it can pay not to ‘put all your eggs in one basket’. The author feels that this “out there” group may/should be the last ‘made’ to make ‘changes.’
For the rest of us living in gentle climes and hospitable topographies, and perhaps already employing (or with an option to) an electric water heating appliance, and whose life/styles are not at risk of bans, Pete’s piece also has some information you might find of some interest. (And possibly some money saving in the future). For our poor ‘gas-ers’, this article is more focused on your having (at some future date) to choose an electric water heating apparatus.
Just for the record, the author resides in a living space surrounded by steep, heavily forested terrain. Because of heavy snowfall and high winds, the electrical utility serving Pete’s abode can be expected to lose power, winter and summer. (And now and then for an extended period). Pete’s neighbors have electric water heaters. Pete has an LPG (propane) fired holding tank water heater. With extended power ‘outs’ the author’s unwavering hot showers are a source of considerable neighborhood want.
Pete’s electric water heater ‘stories’ begin with a basic (graphics supported) description of today’s economically priced, electrical element, mass produced, steel holding tank water heater. And how it works. The author reckons this basic, lowest cost (electric) water heater will be around for some time to come. Two other described designs of electric holding tank water heater the author considers advanced and are ‘expensive’, relatively, will also be discussed. But, Pete’s suspicion: at some point in the future, one of the advanced choices, the heat pump hot water heater may become the mandated design in all new construction and replacements where physics and weather allow. Were this to happen (politics) the reader might have no choice but to install the expensive, technologically advanced heat pump water heater. That is why it is included in this Pipe.
As was with toilets, when super efficiency models became available many communities’ Water Utilities gave rebates that enabled many customers to afford swapping their old water wasting designs for the new, super low-flow models. Pete believes similar programs will be made available for advanced/more efficient water heaters, when “push comes to shove”)
In the third tale-in-line for this Pipe, the author describes an advanced version of the ‘basic’ holding tank electric water heater with a lifetime warrantee, for those readers who today or in the future will be staying put in their homes for “the duration” and who need or want a new water heater. This heater is the Rheem Marathon, a fiberglass tank version (with no need for dielectric anode rods, as discussed, following). You could bequeath this Rheem water heater to your children.
But, before spending time talking the advanced models, let’s dissect, as promised, the ‘long-on-the-job’, basic, 30 to 50 gallon, steel tank, electric, holding-tank, residential water heater.
Wrapped In Blue
Ever wonder what factor most threatens the common ‘holding’, steel tank, water heater? (Yacht owners already know.) Aggressive Water is the culprit. When fresh water is heated to high temperatures, it starts behaving badly. (Like it’s meaner sister, salt water.) It’s molecular ‘arrangements’ play musical chairs, and someone always loses. The water is then ‘hungry’ for molecules it no longer owns. This is now aggressive water. It’s going to fight to get back what it lost.
It just so happens that the steel walls of the tank suffice as nutrient for the aggressive water. Over time aggressive hot water can eat all the way through the walls, floor, or the top of the tank. Major Leak time. Catastrophic, National, property damage results annually.
Davy Jone’s Salvation
For the yachtsman, clamp-on zinc shapes are placed on the hulls underwater metal components, to protect them from ‘being eaten’ (while they are submerged). These added shapes sacrifice themselves to the hungry aggressive water for the sake of the hull. (And need to be replaced cyclically.) To protect the steel tank of the water heater from heated fresh water, its interior is coated with a layer of vitreous (molten) (mucho hot) glass, many times dyed blue,
Somewhat like the saltwater yachtsman protecting their hull with zinc, water heater makers introduce ‘sacrificial’ metal rods (anode’s) into their tanks. These (preferably) magnesium rod forms are replaceable, usually by un-threading them where they were installed. (Sometimes tricky to find where). As the rod is eaten by aggressive water, all’s well. When it’s totally consumed, the aggressive water goes on the warpath and looks at any ‘soft defenses’ in the vitreous tank lining protecting the steel of the tank. The aggressive water likes the steel underneath almost as much as it likes the factory installed magnesium anode rod. As long as the anode is replaced ‘in time’, the heaters life can be extended considerably.
Moons ago the advertising of one competing water heater manufacturer claimed it gave their tanks a ‘Second Coat’ of ‘…Glass Lining…’. When and how (in the manufacturing process) does the steel tank get this glass coating? The tank was complete when molten glass was ‘sprayed’ through existing threaded holes. If the apparatus that applies the molten glass fails to maintain its precision and ‘misses’ or only ‘lightly’ applies the vitreous in one spot or two, that leaves the tank vulnerable to early failure. So, some savvy manufacturer, in their ads, claimed it performed a ‘second coating’. The most thorough job of applying the glass could mean a longer-lived tank. To this day, when I watch my friend Larry the Plumber (larryweingarten.com) use a sawz-all and perform a water heater autopsy for his plumbing class, the inner tanks are often blue (like us?)
Pete’s good friend and mentor, plumber Larry Weingarten, has written a ‘home run’ of a manual showing in easy to understand text and illustrations) how to care for and repair the basic water heaters. His website is: larryweingarten.com. Here you can order a copy, and the curious can also enter Larry’s amazing on-line world of hot water.
O.K., Illus. 1 is the theoretical, standing -‘half’ of the modern day, residential electric water heater.
Steel tanks are made by rolling flat sheets of steel into a desired diameter, forming a tube, and then seam welded. The concave top is a separate piece, stamped or spun, and welded to the tube. On it are threaded openings, usually three or four, depending upon model. #3 The Cold Inlet /dip tube; #1 Hot Outlet tube; #2 the magnesium Anode Rod and possibly a last one for T&P.
Our tank (the ‘Yellowstone’) has the T&P on the upper side, left. #7.
The tank bottom is also a separate part, welded to the tube. Welded to the tank bottom is its base, another separate part.
The walls of the tank will host its own share of holes. Two are for the thread in electrodes #4 & 5. Another is for the T&P Valve (temperature and pressure relief device) #7. #6 Is the threaded hole for the tanks drain valve.
Some water heater’s (depending upon the make and model) will have two extra threaded holes on the side of the heater for cold water-in and hot water-out. This is a tremendous help when the heater needs to be placed in tight quarters. Needless to say, it is a luxury paid for. Equally beneficial is the manufacturer who provides 2 possible locations for the T&P Valve.
The fuse protected electrical power cable #9 in our illustration brings 220 Volts and (in our case) 30 amperes of electrical power to the two thermostatic controls, #10 & 11.
*Unlike thermostatic controls on gas powered water heaters, with a built-in, multi-inch probe, the thermostatic controls on electric water heaters #10 & 11 are flat and mount to a flattened surface on the tanks outside wall. Electrical wiring connects the two thermostats to the two thread-in electrical resistance heating elements #4 & 5.
The Ins and Outs
Cold water enters the tank through #5 the blue dip-tube. Notice the tube hangs down into the tank a long way. It’s that long because designers of the water heater want incoming cold water introduced near the bottom of the tank. (Cold water is ‘heavier’ than hot water.) About the upper 1/3rd. of the tank holds the ‘desirable/useable’ amount of heated water in a cycle. It would not be a good idea to let cold water dilute the temperature of the existing hot water. This would happen if not for the cold-water dip tube.
What else ‘hangs down’ from the top of the tank? Components #1 & 2. Number One (Red) is the hot-out tube. Number Two (White-ish) is the magnesium anode rod. *
*Pete has a confession. The anode rod as drawn is about one-half the length it would be.
The red, hot-outlet tube is much shorter than the blue cold inlet-tube, as one can see. And for a good reason. The longer the tube length is, the cooler the water it will be tapping. Some smart people are the reason lengths are ‘what they be’.
The author thinks/hopes the reader is game to witness a full cycle operation of the modern (electric) two electrical element, holding tank water heater. As mentioned upstream about one-half of the water heaters operating in the U.S. are this type.
Let’s pretend your domicile makes its hot water with a facsimile of the water heater in Illus. 1. And, it’s early A.M. and you get outta bed and head for the shower. Uh Oh. No hot water!!!! (Not a good way to start the day). The heater is eventually (hopefully timely) replaced with a new one. And it is filled with COLD water on its first filling. Then the power is turned on. What happens next? The water heater’s upper e.element (green) #4 is energized. The work performed by the upper e. element heats the water at its level (height) and above, to the set temperature on the thermostat. As the water temperature reaches the setting on the thermostat, power is cut off and it is now sent to the green lower e. element #5.
The water at this lower level of the tank is now heated to the temperature set on the lower thermostat. With this accomplished, the water heater is now at rest and waiting to serve.
A theoretical Someone (again) takes a shower. (This water heater has resting hot water.) By opening the hot port of the shower valve, cold water starts entering the heater (through the dip tube) #3 to the bottom of the tank. The lower thermostat feels it and and sends power to the lower e. element, #11. All this while the therapy of enjoying a hot shower is happening. With the shower valve turned off the reader is now energized!
O.K./ However, if someone else takes another shower right away, the top thermostat #10 will send power to #4 the upper e.element. ONLY ONE Electrical. ELEMENT IS POWERED AT A TIME.
If the water heater’s tank is ‘sized’* correctly, about 90% of the heating will be accomplished by the lower e.element. The Department of Energy has an easy to follow guide to sizing a water heater. You can find it at: https://www.energy.gov/energy saver/sizing-new-water-heater
A Little, side-History
When Pete the Plumber was an apprentice in the late 50’s, water heaters were widely available in four warranties. The first was a 5 yr. warranty with a caveat or two. Next was a 10 yr. Third choice was a 15-year warranty and 4th and last, you could get a 20 yr. warranty. Today? No longer. *caveat
*The author does, though, in the 3rd. discussion involving the Marathon water heater, ‘talk’ you through the construction of this Lifetime Warranty electrical, fiberglass holding tank water heater. It’s his choice and he will tell you why. (Admittedly it is priced for those ‘staying in place’.)
Back to the reasons for the discrepancies (then) in the water heater warranties. These included: tank wall thickness; glass glazing: coats/thickness; number of anodes; number of female iron pipe ports; thickness (and type) of thermal insulation and quality level of heat producing/regulating source. Today, because of Larry Weingarten’s book: The Water Heater Workbook, the reader can ‘assemble’ their own 20 yr. (or more) hot water servant. (Every shower thereafter renews your DIY pride.)
Spit It Out
Because the cost of initial purchase and/or replacement of any holding tank water heater is what it is, a sane person would prefer not to be subjected to it for as long as possible. (It’s a shame that all manufacturers (both gas & electric) are guilty of ‘short-circuiting’ your chances of a long-lived water heater by supplying an inferior drain valve (orange) #6. See: The Water Heater Workbook.
Though this Pipe was intended as a comparative study, repairing water heaters is too large of a topic to include. However, the reader faced with a water heater replacement or repair would be wise to own a copy of Larry’s book.
At/with the final word of “Conundrum” a coffee/tea break is recommended. For those who didn’t perish on this rocky word journey, Pete hopes to ‘see’ you jump in, slide, or fall into “Heat Pump Water Heater’s”, following.
Peter Hemp is a San Francisco East Bay residential plumber and plumbing author and former R & D steam vehicle plumber. His hobbies are ocean kayaking and touring the Left Coast by bicycle.
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