For many experienced plumbers, there really isn't much to replacing a water heater. It's an easy job: just pick up one that matches what's there, maybe strap it in, and leave with the old tank. Whoa. What's wrong with this picture? Just this--it portrays the minimum. Unless you're quite happy with the amount of work you have, the amount of money you make, and the amount of satisfaction your work provides, it's to your advantage to be able to deliver the maximum. When you get jobs because you offer substantial benefits rather than the lowest price, you'll gain long-term, trusting clients and business from their friends, as well.
Stand out from your competition. Hot water can change from bread and butter work to something you can actually be proud of. Many clients will gladly pay for superior work. It's true that people often call just shopping for price. (If you look in the Yellow Pages, you'll see most all the ads shouting, "We cost less!" Inadvertently, plumbers' ads have been training consumers to focus on price for years.) Never mind. Stop and talk to these callers. Tell them how YOU install a heater. Explain how the extra things you do will save them both money and worry because the heater will be safer, perform better, and last much longer than an ordinary installation. Let them know that you can provide simple, ongoing maintenance to at least double the life of their new heater. In most cases, you can keep their heater going for as long as they live there. (Some of our clients' heaters are more than fifty years old.) Many people will be very interested in what you have to say.
Well, what do you need to know to provide this superior installation and follow-up maintenance? It's useful to start with an understanding of the things that make a water heater fail. Most people have only a partial picture of what goes on inside a water heater that affects its longevity. Corrosion, pressure, and heat are the three things that can do a heater in.
How do you control corrosion? The sacrificial anode is the magic wand. All glass-lined tanks have at least one. An anode is a magnesium or aluminum rod suspended inside the tank. It acts like a weak battery when the tank is filled with water. A slight current is generated between the anode and the steel tank (cathode). The current prevents rusting at any exposed steel parts such as welds, fitting penetrations, and pinholes or cracks in the glass coating. The glass does a good job of protecting the tank, but without an anode, a tank would last only a few years.
You don't need to buy an expensive ten-year tank to install a high quality heater. Longer warranted tanks have either a second anode or a more substantial single anode. When you put a new heater in, go ahead and buy a five-year tank. Then transform it into the equivalent of a ten-year tank at less cost by adding a second full-length magnesium anode in the hot outlet. (This combination rod has the magnesium suspended below a plastic-lined steel nipple.)
Anodes corrode away over time. In normal waters the anode should be checked every three to five years. If you can see six inches or more of the rod's core wire, replace it. If the tank has a second rod, you can wait longer, checking every four to six years. Softened water is another story. It's more conductive than normal water and forces anodes to corrode more quickly. Over-softened water can completely consume an anode in six months. Don't ever soften water down to zero hardness. Instead, leave 60-120 parts per million of calcium hardness in the water. That's better for metal piping, as well as anodes.
You can fight corrosion at plumbing hook-ups, too. Just as magnesium anodes corrode to protect steel, steel will corrode to protect brass and copper. Avoid using brass and copper in a steel tank. Instead, use plastic-lined nipples for all hook-ups, such as putting a brass valve or copper flex-line on steel pipe. This prevents damage to the steel. When you connect to the lined nipple with a copper flex-line, you've made a dielectric union that doesn't expose any steel to the water. Now it won't fill up with rust and cause trouble. Sometimes plumbers have trouble with leaky flex-lines. The problem is caused by the rubber washers in the ends of the lines. Heat makes them shrink, and they may leak after a year or so. Go back after six months and snug up the flex-lines, or instruct your client on tightening them. After it's been done once, the flex-lines will perform nicely long term.
Even though they're rated at 150 pounds, water heaters are happiest with fifty to sixty pounds of pressure in them. Both higher pressure and greatly fluctuating pressures can damage the glass lining over time. You've probably heard the crackling noise a new heater can make as it's filled and finishes pressurizing. That's the glass breaking as the steel stretches under pressure. Anodes have to work overtime in such tanks and won't last as long.
And if you hear a tank groan when water is run, take out your 0-200 psi pressure gauge (with a female hose adapter attached) and check pressure at the heater drain. You'll find it's too high. If you flush sediment from such a tank, you may see blue glass shards coming out the hose. Pressure can peel the glass lining off so it's no longer protecting the steel.
Solving pressure problems means both helping your clients and gaining a little more work for yourself. You may need a pressure reducer, expansion tank, and/or relief valve to take care of a high pressure problem. Carry your pressure gauge with you the way a termite inspector carries an ice pick. Use it to troubleshoot and locate problems.
Another pressure problem is water hammer. We've seen water hammer collapse the flue in gas heaters, and that definitely affects their performance! Sometimes water hammer is eliminated just by getting high pressure back down to normal. Otherwise, install water hammer arresters just upstream of any quick-closing valves to quiet down noise.
Heat is the third cause of water heater demise. When temperatures exceed 160 degrees, the glass lining of the tank begins to dissolve. Temperatures higher than 1000 degrees have been measured under heavy sediment build-up in gas heaters. You can control sediment to prevent heat damage and subsequent tank rusting.
You've probably heard the rumbling or popping sounds fuel-fired heaters can make. The noise originates in the sediment, and it seems to be caused by steam. Water overheats in the sediment and expands into bubbles of steam. When these bubbles hit cooler water, they instantly collapse to a tiny fraction of their former steamy selves. (A pound of water is about 1/1700th the size of a pound of steam.) This implosion creates a shock that we hear as rumbling or popping (or a burglar, or a freight train--we've heard some colorful descriptions.)
You can check to see if a tank has sediment. While the heater is firing, turn on a tap (either hot or cold) to lower the household water pressure. If there is a sediment build-up, you will hear the rumbling noise when the tap is opened. It will quiet down when you've closed the tap. At 50 psi water boils at 298 degrees (the higher the pressure the higher the boiling point). If there is sediment, the water trapped in it is overheating. Running a tap will lower the boiling point, so that the overheated water will flash into steam, making the noise we hear. A clean tank can't make that noise.
You need to get rid of the sediment to protect the tank from overheating. Much sediment can be flushed out if there's good water pressure and flow. You'll need a couple of new parts to make the flushing effective. First, replace that troublesome plastic drain valve with a brass ball valve. Use a lined nipple between tank and valve and put a hose adapter in the outboard end of the valve. To keep the valve from getting too hot, use a nipple at least three inches long. That way, scale won't form on the ball and the seals won't get scored when the valve is used. Voila--no drips! Now you have a large, easy-to-use valve that won't plug up with sediment during flushing. Second, remove the heater's factory-installed dip tube. Replace it with one that's curved at the end. Aim it straight back, away from the drain valve. When the valve is opened, the curved dip tube sends the water swirling around the tank, picking up sediment and sweeping it out the drain.
Overheating and noise problems are also caused by aluminum anode debris, as well as calcium sediment. As aluminum corrodes, it's able to produce nearly a thousand times its volume in gelatinous goo. It can make a six-month old tank rumble, creating a complaint you must deal with. So replace aluminum anodes with magnesium rods. (Avoiding aluminum also avoids some serious health problems associated with it.) It's not hard to identify the rods. Aluminum is soft and easy to bend, while magnesium is much stiffer and somewhat springy.
Those are the culprits: corrosion, pressure, and heat. Once you've taken measures to solve and/or prevent problems in these areas, expect the heaters you deal with to last a very long time. Since you also want to offer the safest and most efficient heaters possible, look outside the tank next.
Having a heater that lasts forever is nice, but meaningless if that heater is unsafe. Check out the following items for safety and reliability.
The temperature and pressure relief valve is a piece of plumbing most plumbers fear to touch. We're afraid NOT to. If you service a water heater, guess who the authorities are going to call if the tank later overheats and takes off like a rocket? It's you who will be blamed for the plugged T&P.
T&P valves need testing at least once a year. They can and do get clogged with debris. While testing sometimes results in annoying leaks, more importantly it can show that the valve no longer has the ability to keep the tank from blowing up. If the valve does not allow full flow or if it doesn't re-seat, replace it. In our area, about one of four valves doesn't work correctly. It's useful to hook up the relief valve with a union or flex connector as you run the line to a safe place. The union makes future checks much easier.
Vents can do a variety of unsafe things. They fall off, fill up with mortar from brick chimneys, get their caps plugged or pushed down, and they get installed with too much run and not enough rise, so draft is poor. In addition, heaters are put into rooms with slight negative air pressure, so that air is sometimes or always getting sucked down the vent pipe, spilling combustion fumes. Wait, there's more. Inadequate slope allows condensation to eat holes in the vent. Vents are run past wood, scorching it. And then, people pile boxes, plastic bottles, and other flammables next to hot vents.
Take a good look at the venting of heaters you install or service. Check to be sure that if a vent goes into an attic it also comes out. When the heater is fired up, spillage around the draft hood should be for only a few seconds. If combustibles are stored too near the heater or vent, talk to your clients and make a note on your invoice. If you see evidence of back-drafting, let them know about carbon monoxide detectors. Clients will appreciate your looking out for their safety.
Even with the large earthquakes of the not-too-distant past and with the codes mandating specific strapping, we still see new heaters installed with inadequate bracing. Quakes WILL happen. We just don't know when. Be sure your heaters are correctly strapped.
Probably not life-threatening, leaks can cause a whole lot of costly damage. So look around each job site to see what would be damaged if the water heater leaks. (And if it leaks for three weeks while the owners are in Tahiti?) If nothing will be hurt, you don't need a drain pan. Otherwise, you do. The pan also needs a drain line that's actually hooked up. (We've seen drain pan outlets just covered with duct tape, out of sight behind the heater.)
There are some interesting devices on the market now which are designed to shut off water supply to the heater if it starts leaking. Another option which might give your client peace of mind is a water alarm in the drain pan. To avoid false alarms or damage to the heater, run the drain line from the T&P out separately. Lines from both the T&P and drain pan should end where the homeowner will see them and be alerted to any leak.
Recent energy difficulties have raised awareness in consumers and plumbers alike. The need for efficiency in hot water systems is better understood and accepted. Correct heater sizing is one of the most important factors in the energy picture, but it's often overlooked. If you're called to replace a heater, don't automatically put in the same size. Ask some questions. Did the old tank provide adequate hot water? Have new fixtures been put in (low-flow showers, aerators, front-loading washing machines)? Check older showerheads. If you find an old 8 gpm showerhead, you can probably reduce the heater size by installing a low-flow shower. The energy savings will quickly pay for it. Smaller heaters always have a higher energy factor, due to lower heat loss.
Whatever the size, heaters with good insulation cost little more than their thinner counterparts. If you're installing a new heater and can get those extra inches of insulation to fit into place, your client will thank you for it. Tanks with R-16 insulation are readily available these days, and in popular sizes they can even cost less than the old standard R-8 heaters. Blankets aren't nearly as good as built-in insulation. Even the best blanket won't insulate your heater to R-16 (and you should not cover the top and lower portion of the heater). Another drawback is that blankets cover up safety and operating instructions; they can also hide evidence of leaks.
Go beyond the tank itself and install heat traps on the lines above the tank. Avoid the chattering ball type and install silent ones; you can make your own by using long flex connectors to make an upside-down U in the lines. Heat traps prevent errant BTU's from wandering away.
In addition, insulate those plumbing lines. Insulate as much hot line as you can and the cold line back five feet from the heater, if possible. Use 3/4" thick foam; it takes no more effort than putting in thinner stuff, and it does a much better job. Leave the ends of flex-lines or other unions uncovered, as you may need access and you don't want hidden leaks.
THE END RESULT
It's within your power to give your clients the most satisfactory water heating experience they've ever had. Long service life, safety, and efficiency are intertwined, and serviceability (the things you've built in which make the heater easy to maintain) overlaps all three areas. If you don't set up a heater so it's easy to service, maintenance probably won't happen. Forget trying to offer the cheapest heater. Instead, educate clients a little so they will let you give them an outstanding job. They'll be happy you took the time to show them a better way.
This is an article written years ago, but the message still resonates. Safety must come first!
A water heater exploded inside a restaurant in Southern California last year, killing one man, injuring several others and demolishing the rear of the building. Our purpose in writing about it a year later is not to second guess or affix blame. The precise cause or causes will probably never be known for certain. There is value, however, in looking at possible causes and contributing factors.
The water heater equipment at the El Torito restaurant was a fairly typical installation: a 726,000 BTU boiler, a ½ horse power pump and a 115 gallon, hot water storage tank. Water softening was provided by two adjacent tanks. Where are the potential weak points or trouble spots in such a set-up? We’ll explore several, some relating directly and others indirectly to the explosion.
One direct cause of the explosion was the lack of a temperature and pressure relief (T&P) valve on the storage tank, and a T&P is the last line of defense against overheating. When the system was installed six years earlier it is likely that a T&P was provided in the tank. For whatever reason, the T&P was plugged by the time the explosion occurred on August 1, 1993. You’ve seen leaky relief valves. It’s easy to imagine someone removed the annoyance from the tank, intending to replace it and then forgot about it. There was a pressure relief valve on the boiler, but that would not protect the tank from excess temperature as you’ll see.
One reason the tank explodes was that the water in the tank got too hot and there was no T&P relief. Now, how and why did the water get too hot?
We can deduce with some certainty that rusting was well under way inside the tank. First, the tank was six years old, and tanks which are not maintained, have generally begun to deteriorate by that time. (How many stories have you heard about five-year tanks giving out in five years and one day?) Second, this storage tank was fed with softened water. Since salt in softened water easily doubles or triples the consumption of a tank’s sacrificial anode, this tank had probably been without rust protection for several of its six years. (We’ve seen anodes completely consumed in as little as six months in over-softened water conditions.)
So the tank was most likely rusting away from both inside and out. Any number of conditions could have caused the weakened metal to fail--a restriction on the cold inlet, which blocked the expansion caused by heating, a water hammer caused by an automatic valve, or even a faucet closing. Fluctuation in line pressure could have done it. Or, if one too many molecules of steel rusted away, the bottom of the tank would begin to deform, cracking the already weakened metal and causing it to break. Once broken, a large leak would develop, instantly allowing the super-heated water to flash into steam with explosive results.
To get a clear picture of what happened to the tank at El Torito, you have to re-think your concept of water. Think of water as rocket fuel. And think of the steel tank, which holds the fuel as paper. With enough force, the tank will tear and wrinkle, just like paper does. Imagine that the static pressure involved here is 50 pounds per square inch (psi). The 18 inch diameter of the tank’s bottom has about 354 square inches, so that amounts to 12,700 pounds of pressure against the bottom… over six tons!
With a normal water leak, the pressure will drop as the leak grows, limiting the size of the tear. But with super-heated water/rocket fuel, the pressure will not fall off until much of the water turns to steam. The tank may already be through the roof by then! (Did you know a pound of steam is 1,700 times bigger than a pound of water?)
What ignited the rocket at El Torito? We imagine it was a combination of excessive rusting of the tank, some form of overpressure or water hammer and water which was heated over 212 degrees.
Whether or not incorrect equipment installation, improper equipment operation or equipment failure occurred is a moot point. It’s more productive to focus on the things which will make the system less dangerous.
It’s likely that people monkeyed with the controls, and not knowing all the effects of what they were doing led to an unsafe condition. To avoid this situation in your own work, talk to the people who actually use the equipment. Talk to the dishwasher. Is he satisfied with the hot water supply? Listen to any complaints or comments people have. Although they may not understand how the equipment functions, they know what it does or doesn’t do. Thy will give you the information you need to keep the equipment behaving, and that will help you to keep unskilled hands off the controls. Ask directly if anyone else adjusts or operates the equipment. Look for evidence of others’ work, like loose access covers, wrench marks or inappropriate settings. It’s not in anyone’s best interest to have unskilled hands on the equipment.
A comprehensive service routine and printed forms are needed to make sure regularly scheduled service/maintenance is adequate and complete. Mechanics may lose the ability to really see a system, especially one they’ve taken care of for a long time. Over familiarity can lead them to feel they know what components need maintenance, so some other parts may not be checked as well or as often as they should be.
It’s important to devise and use forms that require service and inspection information to be written down.
Keeping written records is still important even though we all use computers now. I like putting service info directly on the equipment, so it can’t be lost or ignored too easily.
I just finished teaching a class of about fifty maintenance people some of the nuances of water heater repair—and in the process I learned something about my source of strength.
We were playing with some dead water heaters that had been captured on their way to the dump. I like using old heaters as a teaching tool; they have stories to tell about their lives, if you know how to look. In that looking, we were removing pipe nipples from the tops of the heaters—and some were rather stuck.
A few students said, “This is too hard. I can’t do heater maintenance.” I don’t like the word “can’t,” so I jumped in to see if this old white-haired guy could make the stubborn pipe nipple move. I put my trusty Hoe Wrench from 1922 on the nipple and focused. The pipe came loose. Students were surprised!
It happened again twice. A student was unable to budge the pipe nipple (even using my wrench) and I waltzed in and made it spin. The young guys with visible muscles rippling in their arms had no success while the old guy did--what gives?
Finally, someone asked me what my trick was. I had to think for a bit, but I remembered back about forty years when I was shown this: Rest your hand on a friend’s shoulder. Have your friend put both hands on the inside of your elbow and try to bend your arm down. Resist by thinking about your arm and give it all the strength it has to stay straight. In my case, my arm bent despite my best effort. Now put your hand on your friend’s shoulder again, but this time concentrate on the area just under your breast bone as your source of strength and keep your arm straight. Let your friend try to bend your arm and see what happens. In my case, they couldn’t do it. My arm stayed straight!
I’m just a plumber, and I don’t know how this works, but I know it does. It turns out I’d worked this approach into my practice for decades without thinking about it. It’s simply that I refuse to walk away from a job without finishing it, and this “trick” has allowed me to finish every job. The guys who couldn’t make the pipes come loose thought I’d bested them, but really the point was that I’d demonstrated a tool we all have that most of us don’t use. It certainly sounds woo-woo, but with no doubt it works.
There are a couple of other not-so-obvious tricks I’ve learned over the years. For example, the plumber who appears to move the slowest often gets the work done the fastest. When you go to a job, sit down and map out the work in your head before picking up a tool. Understand every step of what you’ll be doing before you start. This way, when you get going on it, things will go together smoothly and you won’t need to re-work anything. When you finish, it will be just as you envisioned. That feels pretty good!
Here’s another trick that helps me work effectively. I’ve noticed that I think in pictures. When I can get a clear picture in my mind of what I’m trying to accomplish, it inevitably works. When I can only get a fuzzy image in my head, it doesn’t work; I wind up needing to figure out a different way. So, when you have the opportunity, see if getting a clear picture before you start works for you on your next project. It just might save you some time and frustration.
The moral of my story? Sometimes it’s the subtle shifts in focus that make your actions powerful.
The man’s toilets were filling with hot water again, and he was upset. In fact he was steamed! He had had to put up with this problem on and off for years. People he had brought into help had been unable to figure it out because they saw troubleshooting strictly as an art. They may have imagined that if they stared long enough and hard enough at the offending toilet, a profound and clear insight into the root of the problem would result - sort of a transcendental experience.
We take a somewhat different approach when troubleshooting hot water systems. The basic premise is that we are dealing with physics, not the occult. Every action by itself is simple and predictable (although it can get interesting when a handful of them are thrown together). So, if metaphysics doesn’t solve your problem, the following practical suggestions may help.
Gathering enough information is the key. It’s important not to decide what the problem is until you actually go and look. You’ll waste time trying to justify your conclusions without seeing the facts in front of you. Listen to your clients. They live with the problem and are far better acquainted with its effects than you are. They can tell you the history of the system and describe how the trouble began. (Was it about the time their six-year-old nephew played hide-and-seek in the mechanical room?) Take it all in before setting out in any one direction.
Next, try to envision the system’s various movements. Use your imagination to follow its water flow and its heat transfer. Shift into fast forward and watch the corrosion processes. Can you see the plug of rust developing at each copper-to-steel connection? In the same way, watch the build-up of scale and sediment. (Could that be why the disc in that swing check valve is stuck open?) Then pretend you’re water. As the hydronics wizard, Dan Holohan, says, “Wander through the pipes… Unleash the power of imagination you had as a child.”
Try the system with a pump on and then off - or a valve open and then closed. Never assume a part works just because it should. (Have you ever opened up a suspicious valve to find the stem broken off and the gate missing? For whatever reason, the plumber before you didn’t replace the valve when the stem snapped off in his hands.) Try not to get tripped up by such mental land mines. Do a thorough examination. Don’t allow yourself to be hurried. If the system won’t release its secrets to you when you ask what’s wrong, ask what’s right. Check these items off your list as you find they behave correctly. Part of the fun is anticipating the results of various tests you devise.
Once you have a clear grasp of a system’s functions, its malfunctions and their causes will become more apparent. You will probably be juggling a great deal of information at this point, and you’ll find it easier to see if you make a detailed schematic. The more accurate your schematic, the easier it will be to spot the effects of variables such as convection or air in the lines.
Don’t disdain the printed word. The answer to your challenge may actually be hiding in the instructions for a piece of equipment, or it might be waiting for you in the technical section of a used book store. Old books can really hit the mark with their common sense answers to “new” problems. (Example: a 1951 book by Watts Regulator recommends installing tempering valves with heat traps to reduce valve scaling in hard water areas. This will also eliminate the full-time cross connection that can occur when a tempering valve “sees” the heat of the stored hot water and scales up in the open position. How many tempering valves do you come across where Watts’ advice was followed?) Relevant information can come from more than just the job-site.
The steamy toilet problem did get fixed. The man had two water heaters with a hot water recirculation line tied back into one of them. Although the tanks were side-by-side, plan changes during construction caused the cold supplies to be separated. When the recirculation pump came on, it pushed water back through the cold inlet of one tank, around, and into the other, heating the entire cold line between them. So, while cold water was expected at the toilets and other fixtures, heated water arrived instead. Once the cloak of mystery had been lifted, a spring check valve was installed in the cold supply of the tank which had the recirc line attached. This kept hot water from backing into the cold line and solved the problem.
The original and somewhat misleading question was “Troubleshooting: Art or Science?” While it’s clear that troubleshooting can be an art, its foundation must rest firmly on method and science. Successful troubleshooting relies on a real marriage of both art and science.
A plumber’s perspective on water heating technology and its implementation.
I met Armin Rudd at the Hot Water Forum in Berkeley. He was giving a talk on combined domestic hot water (DHW) and space heating systems he’s been working with. One puzzling and persistent problem he found has been this bluish grey goo clogging up filters in the system. As a plumber who likes hot water, I told him it was corrosion product from an aluminum anode and he looked a bit stunned.
Having been involved with plumbing since I was fourteen, I’ve been forced to become a fan of elegant simplicity. In the field, things go wrong. The more complex the equipment or its installation, the greater the likelihood of problems. The greater the technical demands on the installer or end user, the bigger chances are of details gone missing or maintenance forgotten. Combining DHW and space heating creates opportunity to build amazingly complex systems that almost beg for a spare bedroom near the equipment room, so the technician is always close at hand. The real challenge is to make things mechanically simple and comprehensible.
Despite the existence of trade schools and many other resources for educating trades-people, most of the training we get in the US is on the job. Our bosses and co-workers share what they know and by making mistakes, we learn what not to do. There is little room in this scenario for the science in books to filter into the plumber’s work, but lots of room for old plumber’s tales. So, it becomes a protective thing plumbers do when they avoid new technology, because personal experience is what they rely on rather than science or other’s research to feel comfortable installing and guaranteeing equipment and systems. Those are only two of the roadblocks to making our use of hot water more efficient and sustainable. But they’re big ones and can be broken down by bringing education and science to the field and at the same time bringing field experience to the lab.
I try to do what’s best for the end user as most plumbers do, and want things to be simple and easily understandable. I try for lowest life-cycle cost, even if it’s not the very most energy efficient. I want comfort for the user, because if it’s not comfortable, the system won’t live a long and fruitful life. Comfort has various faces. It means a comfortable and quiet home, an adequate hot water supply, little waiting for hot water, little time spent fiddling with the system or waiting for the technician, predictability and not too many dollars spent.
Putting all of the above together is what I’ll aim to do. So I’ll begin with the obvious, but sometimes forgotten detail that if we really want efficient housing, we need to look first at the building shell. Shell work can be durable and effective, though I’m still waiting for insulation to be sexy. A good shell adds to user comfort and then allows us to look at technologies like combined space and DHW systems that don’t need to pour out enough heat to warm the entire block. As homes get snug, we find the DHW load exceeds the space heating load, both instant and yearly. For example, filling a bathtub can take a lot of energy, quickly, but heating an efficient home simply doesn’t have that big energy demand; which leads to using one heat source for both and sizing it for DHW loads. Of course, that’s a water heater!
I put shell efficiency first because it’s really the low hanging fruit. Also in that category is plumbing distribution. Jim Lutz, formerly of Lawrence Berkeley Labs has been measuring plumbing system efficiency and sadly, it’s not good. A really efficient shower event delivers 80% of the energy and water that went into the system as usable hot water at the shower head. A bad shower may be 20% efficient. So, install the sort of plumbing distribution Gary Klein has been talking about that can deliver hot water anywhere in the house wasting only one or two cups, (demand plumbing or central core plumbing) and you’ll get to install a smaller water heater!
So far so good. By making the shell of the house and plumbing system efficient, we’ve been able to significantly downsize water heating equipment. That equipment can be many thing such as electric or gas tank type or tankless heater; electric heat pump or in the near future we hope, gas fired heat pump. Solar or heat recovery can reduce the demand further. The concept of simple solar has hardly been looked at or explored seriously for commercialization by anybody I know other than Steve Baer of Zomeworks in New Mexico. http://zomeworks.com .
As an example of what can be done, I built an efficient off grid house that’s heated by solar hot water and a wood stove as back-up. It uses a gravity driven radiant system in the walls. Its claim to fame is the ability to keep the house at 70 degrees with 80 degree water. So, if solar weren’t involved, I could use condensing technology and keep it running in its sweet and most efficient spot. Low grade heat distribution is a natural for condensing technology. It’s not hard to do with hydronic distribution, but harder with air. Did you hear the challenge?
Having been in hot water for years, I’ve seen a range of equipment subjected to a variety of waters and conditions. Hard water is tough on anything that has high heat flux rates. Acidic
water loves to dissolve copper. Dissimilar metals have trouble together in conductive or over-softened water. Not planning for temperature extremes will burst the odd pipe or solar panel tubing. Leaving the plumber’s apprentice alone too long on the job might not be cost effective!
Let’s think about corrosion for a bit. One thing in plumbing you want to corrode is the sacrificial anode in tank type heaters. But thinking it through, metals, as they corrode produce a quantity of corrosion product that is bigger than the original metal. Our experience is that aluminum creates far more than other common metals. Where is all that going to wind up in your system? Magnesium anodes produce less stuff and are not considered unhealthy. So, knowing there will be anode corrosion product and possibly hard water scale and maybe some sand in the bottom of the tank, doesn’t it make sense never to pull water from the bottom of that tank? In the past some manufacturers have done just that and even mixed in brass fittings just to make sure the steel tank rusted to protect the brass. This makes an unwanted rust blockage where the brass screws into the tank. If the anode is doing its job, it will plate out the brass with mineral from the water and block flow there too. So, one bad connection in the wrong place can have three forces working at it to cause trouble.
Perhaps the most common plumber’s tale is that brass or bronze nipples are better in steel tanks than copper. I think it implies the wrong question and sadly, it’s true, but only by a very little bit. These three metals are all in a group, a ways away from steel on the galvanic scale, thus they all have similar desire to make steel rust to protect them. Better is always to use a lined steel nipple in the tank to put distance between different metals, greatly reducing galvanic corrosion.
Plumbers tale number two is that dielectric unions work. A dielectric is usually brass and steel separated by a thin rubber washer, in water. It’s also the only place in a modern potable system where steel is encouraged to be wet. Typically the steel rusts, bridging the rubber washer and eventually the dielectric turns into a seeping, rust filled, flow restricting bump in the line. Using a lined nipple with a flex connector that has a true dielectric in it will give good separation of metals without the problems.
This brings up the concern of stray current corrosion. Anything that blocks electrical current flow in plumbing forces that current to jump off the pipe, swim through the water and land further down the line back on the metallic pipe. The point where current leaves the line will disintegrate. This does make one want to use dielectrics only where absolutely needed. It also promotes jumpering and grounding systems to give the current an easier path to take to get back to earth. Normally, using #6 solid copper wire between hot and cold over a heater and
then running that to the ground bar at the main electric panel is good. Single point grounding prevents trying to force current through the earth and building up differences in voltage between grounds. All this only means you keep any current from flowing through the plumbing and equipment, which is good.
Stray current comes from at least three sources. It used to be common practice to ground the electrical system to metal plumbing. Should any appliance have internal electrical leaks, it would energize the plumbing a bit. Meter repairers have been electrocuted by removing a water meter without jumpering between the two pipes first. I’ve often found leaks in electric heaters where the heating element sheath splits or corrodes, letting water into the element and electricity out. This is easy to test for with a volt ohm meter in the ohms setting. Another source of current in metal lines is simply wiring running close by. It acts as a crude transformer, inducing current in the plumbing. If a known good ground can be brought to suspect plumbing one can test for voltage between the ground and pipe. An extension cord and meter are all that’s needed. It’s common in my area that the main steel supply line to a home gets replaced with PVC. If plumbing was used as a ground path, now it doesn’t work anymore and current will be forced to find new routes. Tying existing plumbing into the main panel’s ground when the water supply is replaced makes sense, but isn’t always done. It turns into a “that’s not my job” moment. A third source of current would be nearby lightning. During a lightning storm might not be a good time to be fooling around looking for leaks to ground or golfing.
About 85% of the US has hard water. That is a concern when trying to get heat quickly into water. I’m lucky in a way that my little corner of the world has water than varies from 40 to over 800 parts per million of total dissolved solids. I used to embarrass my wife by carrying around a total dissolved solids (TDS) pen and checking water at restaurants. A lot of water softening is done where I live. When water is over-softened, tank type heaters live short lives and no protective scale can build up inside copper pipes, leaving them to erode over time. The National Association of Corrosion Engineers suggests leaving 60-120 ppm of TDS in the water after softening. Softener people prefer softening down to zero. Odor problems happen much more often with softened water and with tanks that are too big for the usage they get. Tankless heaters don’t like hard water, we learn from their warranties. In boilers, even a little scale has a dramatic effect on performance. I have not seen a study on the effects of scale on modern tankless heaters, but hope to, because it would let tankless users know whether performance falls off or not with hardness and also help them to know when de-scaling should be done.
Hardness makes things that move inside the plumbing not move so well. Re-circulation lines often have swing check valves that lime up in the open position. Pumps get jammed when scale finds its way into them. Tempering valves all fail. Then there are relief valves. I like to test relief valves on tanks because I don’t want any heater I’ve seen to make the evening news by blowing up. One quarter of the valves I test don’t work for some reason. Of those, about one in ten will not let water through. They are plugged solid with minerals. This happens even when they sit up on top of the heater. I can only guess the anode wants to protect the brass and plates it out with hardness from the water. Still, if one of forty heaters has no protection, we must be relying on good controls to keep heaters on the ground. The problems of hard water can be reduced with appropriate use of materials; not just a well managed softener, but PEX piping, valve stems that don’t de-zincify and provisions for easily flushing any part of the system that could ever need it.
Homes will continue to get more efficient. As they do, combined systems will make better and better sense. We’ll probably need to come up with several system types for different climates, water quality concerns and budgets. Looking at distribution for a moment, I think it useful to consider both air and water as our friends for moving BTUs around. I read that a ½” pipe can carry as many BTU’s as an 8” duct, using about 1/50th as much energy to move them. This suggests simple heating systems could work nicely right now. Just as shell tightening can have a huge effect on the load, it might be useful to look around the house to see where other sources of heat could come from. We may, someday want to intentionally capture or vent out the heat off the back of the fridge, do something useful with attic heat, or see if earth tubes can be designed that stay dry and work as designed.
Even though I’m away from the coast where I live in California, cooling is seldom needed. We do have fairly dry air, so even if cooling were needed, I could use chilled water with little risk of condensation. Where high humidity is the norm, chilled air might be a better medium for moving coolth around.
Linda Wigington formerly of Affordable Comfort is working on the Thousand Home Challenge, http://thousandhomechallenge.com which sets the bar high for reducing home energy use. The people who are on the path for this challenge make a natural testing ground for ideas any of you may have for what makes a good combined system. Linda is creating categories for system types by region and housing type and I’m certain would welcome your involvement.
Although I’ve mentioned a number of technical considerations for combined systems, the biggest difficulties lie with plumber and end user education and expectations. Keeping a plumber on tap somewhere near the design lab couldn’t hurt either. Unless those needs are dealt with, getting good systems installed will remain the exception.
What would plumbing look like if it were designed only for superior performance and durability? What if politics and designing for the lowest common denominator didn’t enter into the thinking?
Let’s start by thinking about what we want the plumbing to do. Assuming now that we’re talking about the hot water system, (because we LIKE hot water) we want the plumbing to deliver clean hot water quickly, in the amounts we need and with little or no waste of either energy or water. We also want the system to behave nicely for an extremely long time, with not a single problem. So, no leaks, no noise and plenty of hot water. Oh, and we want it to be adaptable to future changes in the building.
What would such a system look like? To start, we’d need to know the flow rates of the fixtures. We’d find the lowest flow rates we could that do the job at hand. That might be a 1.5 gpm (or lower) showerhead and kitchen sink and .5 (or better .35) gpm lavatory sinks. We might have appliances like clothes and dishwasher that heat their own water, so no hot line would need to be run to those places. We’d also need to know the pressure in the lines when no water is moving; called static pressure. In addition to knowing those two things, we’ll need to figure out how long the piping runs need to be.
Plumbing design with one main manifold, or possibly distributed manifolds will determine line length. Now, finally, we can size the tubing. A good (and free) tool for this is the System Syzer by Bell and Gossett. It is designed for copper, which likes water flow up to four feet per second. PEX can take ten feet per second if you have adequate pressure! One last thing to consider is water quality. Say it’s acidic. You wouldn’t want to use copper in that case as it won’t hold up. PEX is better for aggressive waters.
Modern plumbers seem hardwired to build straight and square. Modern materials, like PEX tubing don’t need that. They work best using the most direct route and the fewest fittings, so you suffer the least pressure drop, (friction losses) possible. Everything we can do to reduce the volume of water in the lines and decrease friction losses will help with better and faster hot water delivery with the least waste. Pressure compensating aerators and showerheads will help further, by keeping flow the same even when someone else uses water in the house.
One more thing modern plumbers do is to insulate as little of the plumbing as possible. We operate under the misguided idea that it’s not cost effective. Let’s look at this from another perspective. How cost effective will it be in 25 or 50 years? How long will this plumbing be in place? We can be pretty sure that energy and water will never come down in price, so let’s design the system to not need updating during its life. Insulate all of the hot plumbing and even the cold plumbing if it’s installed in a humid climate. This way, we save BTUs and prevent condensation damage, along with improving system performance. And as long as we’re insulating, let’s use thick insulation. A good rule is to use the same thickness as pipe size. Half inch tube gets half inch thick insulation, and so on.
Part of the fun in this is when you understand that the physics say you might be able to use ¼” or even 1/8” tubing to supply fixtures! Such small tubing with so little water in it means you won’t need to wait long at all for hot water to arrive. Yay! It also means the system will cost less than “normal” plumbing as you’re using fewer feet of smaller tubing, which will take less time to install; you’ll be saving gallons and BTUs every day; and you’ll be saving time, not waiting long for hot water to arrive… for as long as you live in the house!
The fittings pictured above are officially called Swoops. A friend, Gary Klein, figured out that fittings like this add almost no friction loss to plumbing, which may let us downsize the pipes. He decides to name the fitting “Swoop”. If you’re installing copper plumbing, this is good. If you’re working with PEX, just bend the tubing as needed with bend supports or long turns and avoid as many 90 degree fittings as possible.
Not many decades ago, we used to design houses so all the wet rooms were fairly close together. This allowed the plumbing and mechanical systems to be rather compact, saving money and increasing efficiency. More recently, we seem to have forgotten how to do this. Wet rooms now are spread out all over the place, as far away from the water heater as possible. Still, “central core” plumbing is a concept to keep in mind when remodeling or building from scratch as it can dramatically increase performance of plumbing and other systems.
Taking it one step further, if you do central core and build a small mechanical room where the machinery of the house lives, it would be pretty simple to build spare ports into the plumbing so more fixtures would be easy to add later on. I’ve also found that it’s possible to build chases where small plumbing can go, like oversized, hollow baseboard or crown molding. This makes adding or servicing the plumbing far easier than having to rip out sheetrock or notch studs.
This is just an overview of some of the possibilities, but you see that we can do a lot to make plumbing serve our needs better and more efficiently if we can just drop some of the commonly accepted limitations.
Without teachers, imagine how long it would take and how painful it would be to learn new stuff. Trial and error over and over again! (That sounds like something Yogi Berra might have said!) I’m lucky that a number of folks have taken me under their collective wings and each in their own way, taught me how to do stuff…(or sometimes how not to do stuff!). There is currently a thread on www.heatinghelp.com at The Wall, titled “Most memorable technician you worked with?” I chimed in about a man I worked with long ago, named Otello. He certainly gave me some different perspectives to work with!
I’ve been lucky with mentors. They have shown me their ways of thinking and their tricks. With multiple perspectives, there becomes almost no problem you can’t get to the root of.
I was taught how to service/rebuild a faucet when I was fourteen, by a man named Hap Hardy, and I’ve been doing it ever since. It takes 10 to 15 minutes to properly fix a faucet. I’m talking about the old style that has a flat rubber washer and a brass seat it rests against. Simply, you reface the seat, giving it a new flat, shiny surface for the rubber to meet up to. You also replace the washer, (or flip it over if the back side is good) and lube everything with faucet grease. It’s not hard. I just had a friend in the SF Bay area who needed this work done on a faucet. She called six plumbers and nobody knew how to do it! And they wanted $150 just to show up. She finally found a handyman who would just change the washer for $75. I need to teach some handy-people how to fix faucets!
This brings me to my next point, which is about passing on what I’ve learned. Being an old guy, it’s my turn to mentor others. Actually I’ve been teaching in some way or another for around forty years. A couple of the guys I’ve worked with went on to become skilled craftsmen in their own right, exceeding my skills in many areas. But I helped get them started. I like sharing what I’ve learned and we really do need the graying workforce to train the next generations, or who will keep all of this infrastructure we have operating?
I’ve got a younger friend who I’m teaching all about the concepts of efficiency. He’s a quick study, so is beginning to understand how so much of what he runs across was done in the normal, inefficient way, and it frustrates him. It’s a good sign that he cares and grasps the underlying reasons for pushing efficiency and durability. Ultimately doing a job well means it will take less of your time and money later. It’s easy to make time for teaching someone who cares. For the novice out there who wants to learn: find a mentor and figure out how you might be useful to that person. I’d happily work on Warren Buffet’s water heater for free if I got to hang around with him and gain some financial wisdom!
The book pictured above was mentioned in an earlier post on teaching. It finally did come out and is bigger and better than before. If you teach or are interested in teaching, this book will quickly move you light years ahead in the art of putting good stuff into other people’s brains.
I take it as my responsibility to those who have mentored me, to help and teach those who are trying now to learn what I’ve learned. They are unlikely to find the info in most schools, other than Union training. Searching for the answer to a question on the internet may help you solve a given problem but doesn’t give you the depth of know how that makes you into an expert. The quickest way to get there is to find a mentor and open your mind so that mentor can pour in some know how!
Here is a water heater that was made in 1895. That makes it about 123 years old. Certainly, we have much more efficient equipment now, right? Well, only perhaps. This is a condensing heater. It’s also a “contact” heater. That means flames/hot flue gasses mingle directly with the water being heated. Similar heaters when actually measured, showed an efficiency of 92%. Your standard modern gas heater is more like 60%. Another interesting thing about this heater is that it has only three moving parts. There just isn’t much to fail, and if it does, it’s easy to fix. Also, as you can see, it’s copper. As long as water is not acidic or aggressive in some other way, this heater won’t fail from corrosion. It’s a demand heater with no electrical use and no standing pilot, so has no standby energy losses either. All those ideas from one heater, called the Ewart’s Royal Geyser!
I collect old heaters and have over 70 of them. Each one presents ideas. Some are good, like this one I’ve been discussing, and some demonstrate ideas that are surprisingly unsafe or uninformed.
Here’s an example of a scary heater. It’s electric, but as you can see with only two prongs, there is no ground. It’s designed to strap to the spout on the kitchen faucet. You turn on the tap, then plug it in and you get a little stream of hot water from it. That was much better/faster than heating water on the stove. A plus to this sort of heater is there are no heat losses in the plumbing. It’s a point-of-use heater and very efficient. The problems however are in managing it correctly… first water flow, then power, or it melts down! But the main problem is the lack of a ground. If you put one hand in the water and your other hand on a metal sink, guess what… you become the ground path. That’s why you don’t see these anymore, because they seemed to like electrocuting children!
But, have a look at this heater: It’s got the same heating element, which is Nichrome wire, exposed directly to the water, but it also has two other things, a ground and a flow switch. This way, it can remain plugged in and can’t use a person as a ground path. It’s actually a heater used for showering. The showerhead mounts directly to the unit, so you get to shower with this device. How exciting can a shower be?! With this, you still have no line or standby losses. Not bad for an old idea.
Old heaters offer up a treasure trove of ideas to consider. Here’s a diagram of one such interesting design: See how the flue inside of it heads up to the top and then turns 180* and heads back down to near the bottom before it exits out the side? Then you’ll see the draft hood down towards the base of the tank. The benefit of this is it greatly reduces the standby loss from the tank as the flue is no longer acting like a chimney and sucking air through the heater, stealing heat all the time. This essentially is a heat trap for the flue, so it only flows when the main burner comes on. It saves lots of energy and has no moving parts. Also it doubles the heat transfer area of the flue for more efficient utilization of heat in the flue gasses.
When electric water heaters were first made, they didn’t seem to perform all that well as the electric supply to homes was small by today’s standards and the heating element might be only 600 or 1000 watts. Today the common element size is 4500 watts. The manufacturers got around this with the idea of a tempering tank: The basic idea was to place the uninsulated tank in a warm place, like boiler room, sunny place or wherever there was “waste” heat available. By doing this, it certainly made the slow electric heater more capable of meeting the demand, and probably reduced complaints to the manufacturer. I see no reason why we can’t do the same thing now and put some waste heat to use.
Using old ideas, it would not be difficult to build a heater that is far more efficient than most modern heaters, one that will last a VERY long time, (think the life of the house it’s installed in) and likely cost little more than a conventional heater to buy. Also, if we keep it very simple, the likelihood of it needing much upkeep is significantly reduced. Think of the savings this imaginary heater will give over its long life. Lastly, if we got used to thinking of life-cycle-cost instead of first cost, we’d be willing to spend a bit more for this heater that should never need replacing. Anyway, food for thought!
I like tools! They make life so much easier if you have the right ones. They make it so there is essentially no job you cannot deal with because of difficult to deal with piping. They make my ageing arms stronger. Pictured is a pipe wrench from 1922. It was made by the Hoe Corporation in New York and it’s my first choice of pipe wrenches when I need one. Why? For starters, it’s automatic. There is no need to turn an adjusting nut. It simply slips over the pipe or fitting and away you go. One benefit of this wrench is that it doesn’t care if what you’re wrenching on is round. Hex or square are fine too as it adjusts automatically. It doesn’t need to grip the pipe at 90 degrees. This wrench can be crooked on the pipe, which lets you work in difficult places with ease compared to the standard Stillson wrench.
This is what’s commonly sold these days, and it just doesn’t have the range of use that older wrenches offer. Imagine trying to play with a pipe that’s in a corner with this tool. It won’t be easy! The Hoe wrench has less trouble in a tight corner and there are other tools that are designed specifically for tight places. I’ve looked for years at garage sale wrenches, but now that we have the internet and specifically the worlds biggest garage sale, Ebay, it’s easier to find nice old tools for fair prices.
I take a two pronged approach when looking for tools. Searching the internet is good, but knowing what I want to be looking for is good too. I’ve found that there are some nice books on old wrenches. Here are two of them. There are more books, but this is a start. Finding the books can be tricky as well, but I’ve found a nifty site: www.addall.com, where they search all the book sites on the web. It’s one stop shopping! Once you’ve perused the books, you ‘ll have a better idea what’s out there that fits your needs and you can be a bit more precise in hunting down these tools. Unlike modern tools, some of the old ones are so well made with high carbon steel (too hard to file), that it’s a real pleasure to find one, clean it up and sharpen it with a grinder (think Dremel) so the teeth can grab the most recalcitrant pipe.
Some tools are just fun. How about this one? Any other plumber that sees it is gonna be a bit jealous! Squeeze the lever and the jaw opens. And note that the handle seems to be designed to put a cheater on. That was not uncommon with the older tools. Thing is, the more different types of tools you carry, the more able you will be to deal with whatever the jobsite is challenging you with. The word “can’t” is something I try to keep out of my vocabulary.
Here’s one more old tool for your consideration. It’s called an Eifel Plierench.
Look at what it can do. It has parallel, geared jaws. This gives you a lot of force. It’s easy to flatten copper pipe with these… Try that with normal pliers! The jaws are adjustable and replaceable with other attachments, like pipe jaws or even a cutter wheel for tubing. It has wire cutters, screwdriver and pry bar built in. Anyway, you get my point, that adding some good old tools to your collection can only help you do your job better and more easily.
New tools have their place as well, but I prefer them for different reasons. For example, I recently got a FLIR One. This is an infra-red device that attaches to your smart phone and lets you see heat or coolth. It can be quite useful in diagnosing a problem or simply being able to “see” things a bit differently.
Here’s an example of three hands. The young, energetic guy who exercises a lot is in the center. The older woman is on the left and her spouse on the right. When looking at buildings, it can show you poor electrical connections, water intrusion, air leakage, or heat loss from pipes and ducts. It can also make you wonder about what we “know” to be true.
For fun, here’s a photo of a lizard sitting on a log. They are supposed to be cold blooded … right?
There are other modern tools for “sniffing” out power in wires without needing to touch them; testers that tell you the condition of the wiring to outlets; line locators that make tracing underground pipes and wires much easier and another favorite is the gas sniffer that works better than my nose for detecting gas leaks. It’s even better than soap for finding leaks. Soap bubbles don’t form if the leak is too fast. For finding tiny leaks in gas or water lines an ultrasonic leak detector is the thing. It hears what we can’t, so saves a lot of time hunting down tricky problems.
The world of tools is big and having the right ones, makes life better. I hope I’ve whetted your appetite for looking into the wide world of tools.
That’s exactly what the guy said when I picked up the phone. I intelligently said “huh?”. He explained that he had called the gas company (who has a policy of not referring contractors) and they referred me, as no other plumber was doing water heater maintenance. Then he called the water company… same story. Finally he called his plumber who also told him to call me. No doubt he wondered how much I’d spent to pay off everybody :~)
I did nothing but work diligently to understand exactly how water heaters do and don’t work and then used that know-how to help clients. I sought out the most knowledgeable hot water people in North America and shared information. Early in my career, I was a generalist… trying to do everything that might ever need doing around a home. That’s a great way to know only a little about a lot of topics, and spend a lot of unpaid time researching info and hunting for parts. A truck is not made big enough that can carry ALL the stuff, (tools and parts) you’ll need if you try to do it all. It’s good and useful to have the generalist’s understanding of things, but understanding a topic in depth makes you the go to person in that field. And a good reputation means you don’t need to worry about whether or not the phone will ring.
Long ago in my area, the plumbers tried to make themselves look good by dissing other plumbers. It’s nothing unusual, but it is unfortunate as it just makes the entire group look untrustworthy. As I was transitioning from generalist to hot water guy, I started asking around, learning what each other plumber liked to do best. When I got calls about doing plumbing other than hot water, I began to refer the work to the plumber who really liked that sort of work. A couple of interesting things happened. I started getting hot water referrals back, and slowly, the plumbers stopped bad-mouthing other plumbers. The latter might just be co-incidence, but it made the local world of plumbing much nicer! The bar was raised.
You may remember a little book called “50 Simple Things You Can do to Save the Earth” (now updated and in print!) by John Javna. My work on hot water was one of the 50 things. That caused thousands of letters to arrive in my mailbox from all over the world. School teachers particularly seemed to use it as a class outline. I needed to buy lots of stamps as this was before the internet took hold, and I got a lot of questions to answer. This became the drive for writing “The Water Heater Workbook” as I got asked the same questions over and over again and began to understand people couldn’t readily find good, truthful answers.
Being considered an expert comes with responsibility. It means you cannot stop learning… you need to stay informed so that you give the best answers possible to those who choose to trust you. As long as I’m putting out thoughts on business and philosophy, there is one more thing I can say with certainty, though I still don’t really understand how it works. If you take care of others, you will be taken care of. Once, I sat down and did the math… In a period of ten years, I had a total of just under two weeks of slow work. That’s pretty good! Additionally, when trouble comes to visit, invariably, good arrives to help me deal with the trouble. Every single time. This always being the case, I’ve learned that worry has no place to stand and bother me from. Worry must find me frustrating!
My point in writing this is not to toot any horns, but rather to share what has worked for me and might work for you, regardless of your field.
Looking back over my working life of nearly 50 years, it seems clear that self sufficiency has always been the best way for me to be useful. Now, mix in a strong interest in water in its many forms and the wide world of animals and you'll know what's important to me.