Saturday, March 21, 2009
Arch Plaster Study
I do a lot of reading. The older I get – and the less time I spend in the field – the more I read all the things that I used to tell myself I would get around to reading when I wasn’t too busy cleaning pools.
And, man, oh man, am I disappointed. For most of my career I’ve just had my head down, focusing on taking care of my pools, going to the odd show here or there, attending a water chemistry seminar now and then. But most of my experience and knowledge was gained poolside. I haven’t paid a lot of attention to what The Experts write – with the exception of Bob Lowry of Lowry Consulting Group. I’ve said it elsewhere in this blog; if you passed the IPSSA water chemistry exam in the last 20 or 25 years, you probably used Mr. Lowry’s books to study for it. He writes great, layman’s explanations of what’s happening in pool and spa water. But other than his stuff and what I’ve picked up on my own from textbooks and the like, I haven’t paid a lot of attention to many of the documents that end up, through their influence, controlling the direction of our industry.
They’re not really documents, per se. You seldom, if ever, see the actual study information – like the real research data, for instance. The internet is huge and space on it is free, or next to free. But still, you never get a look at how tests were really done, or all the data that was collected. Mostly they’re just reports, or, more correctly, brochures. And the ones that seem to have the most stacked decks and the most biased information are the ones from companies selling stuff to us.
Now, if you’re a homeowner wondering what any of this has to do with how salt damaged your pool, it doesn’t. Use the Labels on the right to find blog pieces about your symptoms or about Making Salt Work for your pool, because this blog piece is going to have a huge water chemistry geek factor. But if you’re one of the guys who is in that spot that I was in until about a year ago, busy with your route and your repairs, with your head down and hardly any time to read what it is everybody says are the latest governing documents for how we ought to take care of our pools, take a minute and read this:
There’s this report that’s been rattling around the internet and the trade shows and seminars for the last several years. You can find it here:
Sorry. Dead Link
It’s title on that first website is:
High Cyanuric Acid Levels & Plaster Degradation In Swimming Pools
by Ellen M. Meyer, Ph.D
It’s commonly referred to as the Arch Study. It was a three part study; the first part 5 weeks long, the second part 6 months long, and the third part 4 months long. The gist of the first part of the study is that they put some freshly made plaster coupons into some test tanks and then added as much as 500 ppm cyanuric acid to them, and that over a period of 5 weeks, the cyanuric acid level fell from 500 ppm to about 140 ppm in one tank, and from 200 ppm to about 100 ppm in another tank, and that in both tanks, the cyanuric acid collected as a residue on the surface of the plaster. The fourth paragraph says, “surface analysis showed the accumulation of cyanuric acid on the plaster”.
Okay, so just stop. Stop right there and think for a minute. We’ve all seen pools with 200 ppm stabilizer, right? If you’re honest with yourself, unless you’re Super Poolman, you probably have a handful of pools like that on service right now. I know I do. Most of my pools are under 100. But there are some that are higher. I admit it.
Now, ask yourself a simple question; have you ever seen the cyanuric acid level in those pools drop to as low as 100 ppm and deposit as a residue on the plaster in a 5 week period?
I didn’t think so. In fact, I know so. In fact, it is safe to say – through thirty years of empirical observation - this has never happened anywhere outside the laboratories of Arch Chemicals.
So, how much stabilizer is 500 ppm? Well, it’s about 42 lbs. of stabilizer dissolved into your average 20,000 gallon pool. I’m talking pure, granular stabilizer melted into a freshly plastered backyard pool. Because that’s how this study was done. They took freshly troweled plaster coupons and put them in a tank and put in an amount equal to you putting 42 lbs of stabilizer on Day One of start-up. And how do I know that? Because I finally sat down and gave it several careful readings – something I don’t think many of us have done – and down in the 5th paragraph, in talking about pH control during the 6 month study, they say “because the plaster coupons were new, the pH rose continuously…”
Oh, yeah, that’s Real World. Throwing 42 lbs. of stabilizer into a freshly plastered pool.
So, the assumption I make about that first 5 week test was that they put these new plaster coupons into tanks and didn’t adjust the pH during the 5 week test, and viola! The pH skyrockets and the cyanuric acid falls out of solution, accumulating on the surface of the plaster. Here’s a quote from Dr. Meyer in a Pool & Spa News article: “The cyanuric acid was no longer in solution… It was on the plaster surface, having some kind of affect.”
Now, that’s not really a scathing indictment, is it? Having some kind of affect?
I promise you, if you plastered and filled a 20,000 gallon pool, and on Day One you dissolved 42 lbs. of cyanuric acid into the water, then went away for 5 weeks, when you come back, it would be a logical result to have more than half your cyanuric acid plated out on that pool’s surface.
But then, if you didn’t have any pH control for 5 weeks, you’d have to demo that plaster and start over, because a little cyanuric acid on the surface of the plaster would be the least of your problems.
So, based on these shocking results, this company - that coincidentally makes cal hypo products and owns a few non-chlorine alternative sanitizer labels - decided to do a 6 month tank test. Now they introduce water chemistry parameters. I know that because the say so, a conversation conspicuously absent from the 5 week test. They say the “water in the test tank was adjusted to try and maintain pH between 7.2 and 7.8 and alkalinity between 60 to 100 ppm”. The key phrase there is “try and maintain”. Note that it doesn’t say, like it does later when talking about the 4 month test in test pools “were maintained at…” Old “try and maintain” indicates that boat was missed. So we can assume, from the very language of the report, that, because they were using new plaster coupons, they weren’t able to maintain their own stated water chemistry parameters. You know how it is; three day weekends, somebody forgot, etc.
Too, repeat those water chemistry parameters back to yourself; 7.2 to 7.8 pH and 60 to 100 ppm alkalinity. What happened to 7.4 to 7.6 and 80 to 120? That’s industry standard, isn’t it? Then, after stating these parameters, they contradict them in the next to the last paragraph, where they admit “that pH and alkalinity of the tanks ran on the high side (pH~8, TA~90 ppm), but then they say that despite “the high pH and alkalinity in the test tank, plaster degradation was still seen.
Really? Look at the 3 photos, labeled 100 ppm, 250 ppm & 500 ppm. Those are the ones from the test tanks. Looks like scaling to me, which is exactly what you get when you run your pool water scaling on the Saturation Index.
Now, these “dramatic results” prompted them to do yet a third study; “additional tests were initiated in larger bodies of water where the water balance could be maintained more easily”. They operated five test pools, maintaining their water chemistry at 7.2 to 7.6 pH, alkalinity at 80 to 120 ppm and calcium hardness at 180 to 250.
After four months, they took pictures, which you can see at the bottom of their page. On the left, you have 14X magnified plaster coupon immersed for 4 months in 0 ppm cyanuric acid. Look hard at that photo. Doesn’t that surface look like the beginning of an etched surface? Doesn’t that look like we’ve already burned off the butter and we’re starting to expose the aggregate?
Now look at the plaster coupon on the right, the one that was in the pool with 200-250 ppm cyanuric acid. That’s looks severely etched, doesn’t it? Well, 7.2 pH, 80 ppm alkalinity and 180 ppm calcium hardness is an aggressive environment, all the way up to 80 degrees, assuming a minimum TDS of 430 (their calcium hardness and their cyanuric acid), and all the way up to 90 degrees if the TDS was a little higher, even as little as 80 points higher.
But let’s say that this was done in an air conditioned laboratory in Georgia. A reasonable assumption, right? So, let’s assume a water temperature of 72 degrees. That water is even more corrosive. An extra 0.1, and it being a logarithmic number, 0.1 is a doubling of it’s corrosiveness. Basically, that water is 5 times more corrosive than water balanced to the industry standard of 7.5 pH, 100 ppm TA, 200 minimum Calcium Hardness and average water temp of 78 degrees.
I’m using the handy automated Langelier Index provided by one of the folks who host this study on the internet. You can find it here:
Now, I have a couple of questions about this report.
1. Why did they use such low calcium levels? 180 to 250 isn’t mean calcium as recommended in our industry. When we all start up pools, we make sure the calcium is at least 200 ppm, and I’ve always been told by plaster consultants whose opinions I have come to respect that probably 250 ppm is a better place to start, that 200 ppm is the minimum. And the reason we start our calcium so low is to let the level grow over time, with condensation and the addition of calcium based chlorine products. But why run it so low in the lab? Why not set and hold all pools at 250 or 300 ppm? Because the lower calcium sure clouds the conclusion that it was cyanuric acid, and not out of balance water, that caused the etching.
2. Why is the loss of cyanuric acid only mentioned in the first 5 week study? Did the application of water chemistry parameters in the 2 subsequent tests eliminate that phenomena? Shouldn’t we be able to see the buildup that they talked about in the first test in the 5 photos from the second and third test that accompany this article? Shouldn’t there have been some mention of how they were constantly reintroducing cyanuric acid to the test tanks and test pool in the 6 month and 4 month studies? Remember that quote from Dr. Meyer in a Pool & Spa News article: “The cyanuric acid was no longer in solution… It was on the plaster surface, having some kind of affect.”
Obviously, she’s referring to the first 5 week test. But that quote is mixed in, where the previous paragraph is talking about the 6 and 4 month tests, making it sound like every time you get high stabilizer levels you end up with cyanuric acid falling out of solution. If that were the case, we really wouldn’t have to worry about high stabilizer, would we? Every time it hit 200, we’d just wait a few weeks for it to drop back to 100 and then vacuum the residue to waste.
3. Why in the world would they use freshly troweled plaster coupons to run this test? When would new, uncured plaster ever be exposed to cyanuric acid levels as high as 500 ppm? Not only is it not Real World, it’s not even Real Lab. After all, shouldn’t the lab make an effort to replicate the conditions you’re going to face in your customer’s backyards. Like I said, unless you bring a 50 lbs. bucket of cyanuric acid poolside and dissolve most of it in on Day One of startup, you’re never going to see the conditions they talk about in this report. And by the time you do, you’re going to have two or three year old, very well cured plaster. Of course, there will be folks who will want to play What If on this point. All I can say is that What If is a game for children and not one we ought to be playing in the laboratories and in the professional journals of our industry.
So, why do I care about the Arch Study? Because it is having an affect on our industries perception of cyanuric acid. Look at all the places I’ve found where it’s referenced as the report that shines the light on plaster damage caused by cyanuric acid:
That took five minutes of googling to come up with those links. And it doesn’t even scratch the surface of all the times this study is linked to in the forums - or the Finger Pulling Contest, as I like to call them - and probably 50 or 100 times throughout the thousands of forum threads discussing pools and plaster problems.
But now, whenever people google for the Arch Plaster Study, a link to this blog piece will come up as well.
What irritates me the most is how easily we were all duped. Honestly, why didn’t everyone say to themselves, “200 ppm stabilizer in the water may be high, but if I wait 5 weeks half of it is not going to fall out of solution, UNLESS I jack around with the water chemistry so much that EVERYTHING is going to fall out of solution.”
And that was the first chart on the page. We’ve all sat here and looked at that for all these years, and none of us, me included, has stopped to say, “Hey, wait a minute. That never happens.”
Is it just politeness that causes us to not ask those basic questions? I mean, when knowledgeable people have interviewed Dr. Meyer over the years, didn’t it come up? Something like, “Gosh, Dr. Meyer, you’re the first person in the history of history to report a 50 to 70% loss of cyanuric acid over a 5 week period. Are you sure you were watching that pH and not, intentionally or unintentionally, creating an environment where that was the only logical outcome?”
The Elephant in the Room, as it were.
Or is it because this report supports what a lot of people want to believe about cyanuric acid, and so it becomes the Straw Man for that camp? If you’re face is reddening as you read this, then maybe there’s some truth to that.
The craziest thing about all this is, I’ve heard there are people trying to DUPLICATE THE RESULTS OF THIS TEST and consider their tests failures when they don’t achieve the same results. You see, this thing has become the standard that other efforts are gauged by. It is now assumed that cyanuric acid damages plaster and it’s just a matter of holding your tongue right to achieve the same “proof” that Dr. Meyer achieved.
All I know is this thing gets referenced all the time, usually as “recent studies indicate that large quantities of cyanuric acid can even damage plaster”.
I’ve said it before and I’ll say it again: Lions and Tigers and Bears, oh my!
This study is being used by different groups of people to different ends. The folks at Arch are using it to generate heat for cya based products and a bump for sales of their calcium based chlorine and another reason for people to consider their alternative sanitizers, like Baquacil. People have argued with me that I’m wrong there because Arch also sells cya based products, too. Well, how is encouraging people to keep their cya level between 25 and 50 ppm anything but good for trichlor sales?
That tricity link is on the website of a company that’s big on UV sanitizing. There’s nothing wrong with that. UV sanitizing works and it’s not a scam to be selling the units. And throwing rocks at high cyanuric acid won’t hurt those sales, either.
This report supports a philosophy, a philosophy that high cyanuric acid is bad for us. And it is. The more I read and research, the more convinced I become that high levels of cyanuric acid are inhibiting our ability to effectively combat the growing threat of cryptosporidium outbreaks. Too, from what I've read, it does have the general effect, in high levels, of reducing the kill time of chlorine.
But it doesn’t destroy plaster. Not in the Real World. If a guy lets his pool get to 200 or 300 or 500 ppm cyanuric acid, he’s got enough other bad water chemistry habits to destroy the plaster without cyanuric acid having anything to do with it.
Now, I tried to play fair on this. I e-mailed Dr. Meyer on February 28th and asked her, “when you raised cyanuric acid to 250 and 500 ppm, did you use any correction factor on your observed TA?”
On March, 13th, she wrote back that, “yes, we did use a correction factor on our observed TA for the pool study that was run. We subtracted 1/3 of our CYA reading from the observed total alkalinity to get the carbonate alkalinity.”
I wrote again on March 14th to ask her about the issues of the cyanuric acid falling out of solution, and asked why they used new plaster vice cured plaster coupons for their tests.
She has not responded. If she does, and if she can explain any of this, then I’ll gladly amend what I’ve posted here.
Friday, March 13, 2009
The Trouble With Heaters, Take III (Updated 5/15/10)
I don’t know if many of you watched The Daily Show last night. Jim Cramer, that bald headed liar from Mad Money went on Jon Stewart’s show and did everything but crawl across hot coals on his hands and knees to plead his mea culpa for all the years he spent manipulating markets for a Fast Buck as a hedge fund manager, followed by his recent stint on TV where he and his ilk have led the Average Investor to the Slaughter for Big Business.
Stewart gave him Hell, and all Cramer did was sit there and grin like an idiot and take it, nod and shrug his agreement with everything Jon said, which included that some of Cramer’s pronouncements of how to manipulate stock prices bordered on the criminal.
It was Great! And it dovetails nicely with another bit of news I came across this past week. Jack Welch, the former CEO of GE and world renowned Corporate Cutthroat has repented. Here’s a link to a recent Financial Times article where the managerial guru now says, “"On the face of it, shareholder value is the dumbest idea in the world… Shareholder value is a result, not a strategy . . . Your main constituencies are your employees, your customers and your products.
You see, there’s been a culture for many years in this country, a global culture, actually, a culture that was lionized by the success of Jack Welch in particular, to drive shareholder value as your only guiding principal. Everything was subordinate to that. Everything was based on how it affected shareholder value, which was a combination of stock price and dividends returned to the shareholder.
Now, the Man Who Made It Famous has recanted. He has seen the errors of his way and prostrated himself before the international financial press and acknowledged his errors.
You know, you can see the ripple effect of that philosophy in our industry, especially with our swimming pool heaters. A quick study of heater warranties over the last 8 or so years yields all you need to know of how our manufacturers were infected by the Shareholder Value phenomenon. You see, since the advent of salt systems, heater warranties have plummeted from a typical 5 years for most everything in the box, except for a 2 year warranty on a short list of items that included the heat exchangers, to a one year limited warranty. Under the old warranty, the headers, the devices on either end of the heat exchanger that hold it together, were traditionally warranted for 5 years.
It’s a Cause and Effect kind of a thing. Salt comes along, heater problems skyrocket – I’ll cite particulars to back up that claim in a minute – and the result is a scramble to protect shareholder value by paring down the warranty to an innocuous one year, leaving their customers twisting in the wind.
That’s been our culture for many years. You Go Along to Get Along. If Hayward dumps a dog of a cleaner on the market - and they did - the worst thing anybody says is Nothing. If Jandy marries up a heater to a salt system on a pool and the salt causes the heater to have a failure mode that is absolutely beyond doubt the problem of the salt, unless Jandy makes note of it in a tech bulletin, you Say Nothing.
Until recently, all of this has been a successful model for driving shareholder value. Let’s look at the effects of this by taking a closer look at heater warranties.
The standard warranty on, for example, the Jandy LT/LX heater is one year, and when you read the warranty on the last page of the Owner’s Manual, it lists several exclusions, and #3 on that list of exclusions is:
“Not maintaining a proper chemical balance in your pool and/or spa [pH level between 7.2 and 7.8, Total Alkalinity (TA) between 80 to 120 ppm, Total Dissolved Solids (TDS) less than 2000].”
With Hayward, their warranty is also one year, and as restrictive as Jandy's (see Hayward Onwer's Manual page 14). Under Exceptions, they state: Leakage substantially contributed to by sediment, lime precipitate and/or higher than normal dissolved solids (pH above 7.8) in the tank, copper tubes or waterways".
Higher than normal dissolved solids (pH above 7.8) leaves a lot to the interpretation of whoever shows up to field your complaint. Most salt pools will have constant excursions into the range of 7.8 and above. That's the nature of the beast. So, it's hard to say what they intend with this exclusion.
In their warranty information, Raypak provides a one year warranty, and excludes the situation of "not maintaining a proper chemical balance (PH level must be between 7.4 and 7.8 and total alkalinity between 100 and 150 PPM. Total dissolved solids (TDS) must be no greater than 3000 PPM)".
Pentair has the worst availability for warranty information. They don't post any warranty information anywhere in the public domain. They just say that the warranty info is included on a card that's inside the box when you buy the heater. I don't particularly feel like buying a heater to complete this blog piece.
I have several Pentair and Teledyne Laars (now Jandy) heater Owner’s Manual from as recently as 2003 and in it they specified the industry standard, at the time, 5 year/2 year warranty that I discussed earlier.
What’s particularly tricky here is navigating the water chemistry parameters in light of the addition of salt to as much as 35% of the pools out there. They’ve stuck with their pre-salt water chemistry parameters for TDS. Jandy is less than 2,000 ppm, Raypak is less than 3,000 ppm, Hayward is “higher than normal” and Pentair is unknown. In fact, Jandy makes a point in there 2003/04 LX/LT Owner’s Manual of pointing out that their water chemistry concentration levels are taken from Basic Pool & Spa Technology published by NSPI. NSPI doesn’t exist today. The Association of Pool & Spa Professionals (APSP) has taken their place as the industry recognized advisors on water chemistry standards.
APSP’s thinking on TDS has evolved quite a bit since salt came along. They used to say 3,000 ppm was the upper limit for TDS. Then, they decided that didn’t give enough allowance for the minimum 3,500 ppm salt (TDS) required for those systems. So they amended it to be 1,500 ppm above Start Up level. In other words, if you had 400 ppm TDS tap water, and you added 3,500 ppm salt (more TDS) to it, then your Start UP level would be 3,900 ppm. So your upper limit for that pool would be 5,400 ppm TDS. That’s what APSP and RWQ (Recreational Water Quality) folks say. And they are the industry recognized experts.
Read all about APSP's take on TDS & salty water HERE
But swimming pool heater manufacturers have stuck with 2,000 and 3,000 ppm TDS limits. Salt is definitely part of TDS, so it's hard to imagine that any of these heaters would be covered for any warranty issues related to high TDS. But that’s okay, because they’ve reduced the length of the warranty from the old 5/2 year warranty to one year only.
Do you see the pattern emerging here? They’ve done a brilliant job of protecting shareholder value at the expense of the reputation of their products and at the expense of their customers.
The thing that feeds into this, the Smoking Gun, as it were, comes from the heater manufacturers themselves, when they started offering cupro nickel heat exchanger upgrades on some of their swimming pool heaters right in the middle of the Salt Storm. You see, heat exchangers have turned out to be the most expensive failure items with salt. That and a few other components I’ll talk about later. The heat exchangers fail mainly through the mechanisms of impingement corrosion and erosion corrosion.
I would say that in Texas – at least in the Dallas/Fort Worth area – more than 90% of the pools are built with a heater. Mostly those heaters are 400,000 BTU gas fired heaters. They last anywhere from 7 to 10 years – unless of course it’s a Hayward H400 or a Pentair Mini Max Lo NOX TSI. If you have one of those, your mileage will definitely vary, if-ya-know-what-I-mean. But then, after many years of faithful, or not so faithful service, your heater breaks and the Repair Pool Guy tells you it’s going to be “about $1,000” to get it back in shape. That’s when you have to decide whether you want to be the proud owner of a well maintained Classic Heater, or you buy a new one or – and we hate it when you go this way – you decide you can live without a heater.
If it’s a pool only, then it’s usually live without. If it’s a pool/spa with a computer, then you might be the kind of folks who use your spa enough to cough up the $3,000 for a new heater, installed.
I wrote a blog piece back HERE about a pool owner who uses his pool every day, and that means that with our Dallas weather, he’s using his heater about 6 months of the year. Since he has a salt system, he goes through heaters about every three years, instead of the 7 to 10 years that non-salt pool owners get out of theirs. But he loves that salt. And we love selling him heaters, and we did advise him that he could make them last longer if he just got rid of that salt – commonly referred to as Due Diligence, something often lacking in this, and most other industries – but, like I said, he loves that salt. So, it’s a match made in heaven.
So, three of the heater manufacturers (Raypak, Hayward & Pentair) have added the option to upgrade to a cupro nickel heat exchanger to combat the Impingement/Erosion Corrosion. The heat exchanger is the part of the heater that the water actually flows through. You heat up the finned metal tubing that constitutes the heat exchanger with an open flame, and that makes the water hot. Used to be they were all made of copper. Inexpensive, long lasting copper. Not so much any more.
The reason they’re offering cupro nickel is that a standard copper heat exchanger isn’t designed to stand up to the flow rate of water that has 3,500 ppm salt plus background TDS (Total Dissolved Solids). By that, I mean everything else that’s in the water; calcium, manganese, stabilizer, etc. That’s what I was saying earlier about how the heater manufacturers haven’t amended their position on TDS, even though all of those manufacturers except Raypak also sell a line of salt chlorine generators.
About a year ago, I was communicating with someone who has been a frequent contributor - on background – to this blog. I asked him what he knew about Impingement/Erosion corrosion, the type of corrosion your heater suffers from when the TDS of the water goes too high for your flow rate. And this is what he said then, quoting from the text of a water chemistry seminar he had attended:
“The actual text… is ‘Erosion itself is not corrosion. However, even mildly abrasive conditions may remove a corrosion film from a surface which is protective of a substrate, thus exposing a fresh metal to corrode and thereby accelerate damage. In fresh water pools it is known that flow-rates above 7 to 8 ft/sec will erode copper piping and may remove a protective film from the substrate's surface exposing fresh metal to corrode, accelerating the damage… TDS will accelerate both the galvanic and erosion deterioration processes. High TDS will allow more electric currents to be conducted and will cause copper piping to erode at flow rates in excess of 2.3 ft/sec.’ ”
You see, a certain amount of corrosion can be a good thing. Take copper, for instance. We’ve all seen how a copper portico will weather and turn green with age. That green is a form of corrosion, a tarnish that develops and seals the surface, protecting the underlying strata from any further corrosion. Or like the black tarnish that shows up on silver. That’s oxidation. And what are other names for oxidation? Rust. Corrosion. That’s why ships at sea will use a lot of brass. Because the brass will get that same green tarnish that copper gets – because brass is mostly copper – and that tarnish protects it. On commercial vessels, that’s why they don’t polish their brass. I remember in the Navy we used to polish the brass all the time. “Work it May, Shine it Must” was what they used to tell us. All that effort defeated the purpose of why brass was chosen in the first place. Yet another reason why the term Naval Intelligence in an oxymoron.
So, when you’ve got a 2 horsepower pump pushing 5,000 ppm TDS water through a copper heat exchanger at velocities in excess of 2.3 ft/sec, you start stripping off that protective coating. The result, over time, is a failed copper heat exchanger.
The other thing that is going on is Galvanic Corrosion, also known as Stray Current Corrosion, which I’ve talked about ad nauseam elsewhere in this blog (see the Label Stray Current Corrosion to your right).
So, it’s better for your salt pool if you make sure that the next heater you buy has a cupro nickel heat exchanger. That will make it more resistant to the effects of impingement, or erosion, corrosion.
Another factor, and in fact A Very Big Factor, is your style of heat exchanger. There are two types out there.
The first, and most common type is where a bundle of parallel tubes sits over the burner tray. The water shoots straight down the first tube, makes a 180 degree turn and shoots straight back up the next tube, another 180 degree turn and etc, usually for nine tubes.
The second type is where a coil of copper or cupro nickel tubing is wrapped around a burner tray, with the water navigating a constant curve through the heat exchanger.
The second type is better. But don’t take my word for it. Here’s a link to the ASM Handbook where they talk about these forms of corrosion.
In here they say that most impingement or erosion corrosion damage “occurs first at locations where directions of flow changes, such as elbows or U-bends. Large radius bends are less susceptible to such damage”.
So, here are the heaters that offer the second type of heat exchanger, the one without the 180 degree U-bends, the ones with the coiled tubing around the burner tray, also known as the “large radius bends”:
Sta Rite Max E Therm & Pentair Master Temp.
That’s it. They are, in fact, the same heater. I’m not saying that Pentair bought Sta Rite just so they could get their hands on the Sta Rite heater and put it in a crème colored box, but Pentair bought Sta Rite just so they could get their hands on the Sta Rite heater and put it in a crème colored box.
A Very Good Move.
They’re both great heaters. I have heard of heat exchanger failures with these heaters at the inlet/outlet plate with salt pools, and I heard that from someone who's reputation is sterling in relating data to me about frequent and common failures in pool equipment, but that’s not been my direct experience with the heater.
But, once again, referring to the ASM Handbook, page 999: "When impingement attack occurs in heat exchangers... it is usually confined to a short distance on the inlet end of the tube where the fluid flow is turbulent". That's exactly what my source with the sterling reputation has been telling me.
And now this heater comes with a cupro-nickel upgrade. Your pool professional may not even know about it yet. It's not yet stocked at the wholesale distributors. It's the Catch-22 of distribution; in order for them to regularly stock something, they have to have a history of orders for it. But for you to get something they don't normally stock you have to pay freight from the manufacturer. Add the extra cost of the cupro-nickel heat exchanger and you are probably talking several hundred dollars more. But it's worth every penny.
A new heat exchanger installed is over $1,000.00, and I’ve been noticing a lot of people that got to this blog by Googling for “damaged heat exchanger salt pool”, or variations on that theme. So, it is a worthy investment.
And here’s the Smoking Gun I was talking about. In December, 2006, Hayward had a brochure on their H400 heaters that read: “Cupro nickel is a supremely resilient material that provides product durability and longevity. Cupro nickel aligns well with today’s popular salt -based systems and offers outstanding corrosion resistance".
Yet their warranty as of today is that “higher than normal dissolved solids (pH above 7.8)” will void your one year limited warranty.
These are all things that, once again, dovetail nicely into protecting shareholder value. But over time, as all major corporations are learning the shortcomings of shareholder values as a strategy, it has adversely affected the reputation of their products and the patience of their customers.
Here are some of the real tragedies that have arisen out of Heaters with Salt:
The Jandy LT & LX heaters have a dry well for the high limit switches. The way it works is that these brass dry wells are set into the plastic inlet/outlet header and the high limit switches are pressed against that brass surface. That way, as the water rushes through the header, it’s heat will be transferred to these switches via the brass dry well. That keeps the high limit switch dry so that it won’t become corroded while still allowing it to accurately sense the water temperature. This is how we avoid a runaway heater. If the temperature of the water gets up to 135 degrees, then the first switch will turn off the heater. And if that part fails, then the second high limit will turn it off when it reaches 150 degrees. It’s a great system and all heaters have similar safety devices.
If you look in the Jandy LX/LT Owner’s Manual, you won’t find any mention of the brass wells. On the parts diagram, they show an exploded view of the inlet/outlet header, and they picture the high limit switch assembly. But no brass wells. So, why is all this important?
Because if you put this heater on a pool with a salt system, especially the salt system that Zodiac makes because it uses 4,000 ppm salt, which is even more corrosive than the 3,500 ppm that most of the others use, my experience is that within a year or two, you’ll have your first high limit failure. The threads of the brass well fail and allow water, salty water, to enter into the dry well and corrode the high limit switches. Not a big deal, right? Just replace the high limits and you’re back in business. Problem is, the next time it happens is sooner than the last time. And the next time is sooner than that, etc. You see, the corrosion on the threads gets worse and worse.
So, what’s a mother to do? Well, if you talk to Jandy, at first they tell you to replace the header. But when you price it out and figure that with labor you’re looking at somewhere near $1,000.00 for the job, you call them back and tell them that you’ll recommend your customer buy a different heater before you do that. Then they tell you about this little kit they have, called the LX/LT Sensor Stud Assembly Replacement Kit, Part Number R0383200. It’s carded for easy display. How funny is that? A part that’s not even detailed in the Owner’s Manual, but they had enough call for it that they carded it for wall display.
You order the kit and go take the heater apart, and I mean take it completely apart to get to this thing, and you put the new brass dry well in and you replace the corroded high limits, too, and you’re done for around $350 to $450, depending on how fast you work and what your labor rates are.
Then, in a year or two you get to do it again.
That’s why I strongly recommend against installing a Jandy LT or LX heater anywhere you have a salt system installed.
Now, people will say, “Hey, Pool Guy. Where do you get off badmouthing a perfectly good heater because someone told you they saw something happen on a pool somewhere?”
Allow me to retort: I have 16 pools on service with LT heaters. 13 of them have salt systems and the other three have tablet feeders. I got all those pools on service when they were brand new. Since I put them on service, 11 of the salt pools have had high limit failures, most of them numerous times. None of the pools with tablet feeders have had high limit failures. Fortunately, most of the failures occurred during the three year extended warranty that comes with a new pool when all the equipment is from a single manufacturer. But now they’re all out of warranty and the homeowners are facing these annual repair bills, with no end in sight. Their options are about $150 to $185 per occurrence for high limit switch failures, $350 to $450 per occurrence for dry well & high limit switch replacement, or about $1,000 for inlet/outlet header replacement, or about $3,000 to buy a new heater that doesn’t have this problem.
Now, I’m just a pool cleaner. And my ethic has always been to never sell anything to a customer that isn’t going to work out for them, and if I inadvertently do, go back and clean up my mess. Because just as Jack Welch and Jim Cramer and all the guys at Bear Stearns and AIG et al are finally starting to understand, your main constituencies are your customers and your products.
You see, these are the things that irritated me the most about the Salt Revolution; how cavalierly they threw salt water at pool heaters. It was good for quarterly profitability and for Hitting the Numbers. But, it turns out, not good for much else.