Information on the Original PUR Watermakers


You can use the following links to quickly jump to a topic of your choice. Note: The PUR brand name is correctly spelled with a long accent over the capital "U." For the sake of simplicity, I've omitted the accent in the following references to that brand. The PUR brand name is now a trademark of Proctor & Gamble, Inc.


A Bit of Company History  When I first became associated with this watermaker company (circa 1996), they were known as Recovery Engineering, Inc., operating out of Minneapolis, Minnesota. Some years prior to my association with them, they had engineered a small, manually operated, reverse osmosis watermaker which they sold to the U.S. military, to be used as emergency survival equipment in military applications. The product was a great success and the beginning of the company's financial growth. It's still available as the Survivor 35—and still a great choice for a ditchbag. They also manufacture a smaller hand-operated desalinator, the Survivor 06.

As later explained to me by the company president, Alan Lizee, part of their military contract required that they make an effort to develop a similar product for commercial applications. As a result of that effort, Recovery Engineering produced their first commercial product, the well-known PowerSurvivor 35. During the ensuing years, the Model 35 became the best-known—and best-selling—watermaker available for small cruising vessels. It was unique among the few watermakers then on the market since it was capable of being manually operated, if necessary. This feature was obviously an important selling point to cruisers.

Following the dramatic success of the Model 35, the company decided to introduce more models, most notably the Model 80, which had double the output capacity of the Model 35. In the later 1990's, they worked hard to develop other water purification products intended for domestic household use. If you were accustomed to watching television in those years, you will no doubt recall the numerous advertisements for "PUR" water treatment products designed for the household. These too became a great commercial success. In fact, the commercial success of their domestic products grew so rapidly that, within a few short years, the marine watermaker division shrank to a very small part of the company's operations.

Commercial success is difficult to conceal. Sometime in the late 1990's, the mega-corporation, Proctor & Gamble, Inc. (P&G), took notice. To make a long story short, attracted by the rapid success of PUR's domestic water treatment products, they decided to acquire Recovery Engineering. As a result, P&G made a tender offer to purchase the company, offering to buy all of its outstanding stock at a price about double its then current share value. Need I say more? Recovery Engineering was quickly acquired by P&G. I was personally delighted, since I had previously bought a few hundred shares of Recovery Engineering stock! This was one of the very few financial windfalls I've experienced in my life.

P&G was primarily interested in Recovery Engineering's domestic products. The marine watermaker division, by then an almost insignificant part of the operations, was not only small peanuts, but was also considered to be a high-liability, low-profit part of the business. For the next several years, the watermaker division atrophied in the corner, neglected and virtually unsupported by the new parent company.

It's important to note that, shortly before the P&G acquisition, Recovery Engineering had developed an entirely new line of watermakers for the cruising community. The Model 40E was to succeed the ubiquitous Model 35, the original Model 80 was slightly improved to become the Model 80E, and a new model, the 160E, with double again the output capacity of the Model 80, was introduced. This line of watermakers was called the Endurance series. This is the origin of the "E" designation in the model numbers of the current line of watermakers.

Under the patronage of P&G, the recently introduced Endurance series languished. As always with the introduction of new products, there will be unforeseen engineering problems and, indeed, there were. But the watermaker division was hard-pressed to obtain the support they needed from the new parent company to correct the problems. And that's pretty much the way things remained for a couple of years.

Fortunately, after a couple of years, the small RO (reverse osmosis) marine watermaker division caught the eye of a Swiss company named Katadyn. The Katadyn people had a well-established worldwide reputation for manufacturing high quality and extremely reliable water purification devices, including many designed for backpackers and emergency rescue teams. They decided to buy the watermaker operations from P&G.

It's my personal hunch that the Swiss didn't fully realize exactly what they were buying—specifically the unaddressed engineering problems. They soon found out and, to their credit, they set about correcting the problems as soon as they were recognized. First, all manufacturing was relocated to Switzerland. Second, they responded rapidly to correct the pre-existing problems they had inherited (see the following survey of "PUR Problems").

So, what's the bottom line?  Based on my many years of experience in troubleshooting watermaker problems within the cruising community (see the "Introduction" link in the navigation menu), Katadyn's acquisition of Recovery Engineering's original watermaker division from P&G has been an immense benefit to the owners of original PUR units. Not only are the new units manufactured by Katadyn of significantly better quality, but Katadyn has bitten the bullet and done everything possible to correct the problems encountered by owners of original PUR units. They didn't need to do this—but I think the fact that they did speaks volumes about the kind of company they are.

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Known Problems With PUR Watermakers: Following is a list of the main problems, from my experience, associated with Model 40E watermakers manufactured by Recovery Engineering under the "PUR" brand name. The problems listed are of no concern to owners of Katadyn brand watermakers, since Katadyn rapidly addressed all of the defects they inherited when they acquired the PUR watermaker division from P&G.

Defective Piston Shaft: The early units of all the "Endurance" models of watermakers produced by Recovery Engineering, which includes the 40E, 80E and 160E, included a piston shaft that had a dark ceramic coating. Although the coating seemed like a good idea at the time, problems soon emerged in the field. For some reason, the stainless steel shaft under the coating tended to rust. As the rust swelled, it cracked the ceramic coating, which then chipped off. The resulting rough surface of the shaft quickly damaged the rubber shaft seals and the watermaker would leak seawater. The leaking seawater often found its way to the area where the stainless steel pump body is bolted to the cast aluminum gearbox. Serious corrosion damage to the gearbox flange quickly followed. If not detected soon enough, damage to the gearbox could become extensive enough to require its replacement, which was both expensive and usually very inconvenient for the owner.

Discovery of the problem came slowly for two reasons. First, since the volume of leaking seawater was rather small, the quantity of product water output was not noticeably affected. Second, the original PUR owner's manual incorrectly stated that the watermaker might leak a little (see my comments below concerning the original PUR owner's manual). The typical owner was unaware that there was a problem as long as the watermaker was still producing a reasonable quantity of good product water, even if the unit leaked a little. Eventual realization of the problem was the result of my personal observations over several years of servicing these units within the cruising community in Mexico. My feedback to the company resulted in several attempts to correct the problem while still retaining the ceramic coating, none of which were successful. It was not until Katadyn took over that the problem was finally eliminated.

The actual solution turned out to be quite simple:  the ceramic coating was abandoned altogether. There were literally thousands of the veritable Model 35 units still working on boats all over the world, and its piston shaft was plain, uncoated stainless steel! In all my years of servicing Model 35s, I've never encountered one with a defective piston Old and new piston shafts shaft. The change also meant lower manufacturing costs for Katadyn, since the plain shaft costs considerably less than the original with its ceramic coating.

Once the problem was recognized and corrected, Katadyn, to their undying credit, initiated a proactive effort to find owners of original PUR units and replace defective piston shafts. As of mid-2009, when I stopped cruising, this effort was still ongoing. Replacing piston shafts at no charge was an important part of my responsibilities as I visited cruisers in various ports and anchorages throughout the western hemisphere.

The picture on the upper left illustrates the distinct difference between defective shafts and the new version installed in Katadyn units:  the coating on the original shafts was a dark blue-black or brown-black color, while the new shaft is plain stainless steel. If you own an original PUR Model 40E watermaker, and have determined that you have the old-style piston shaft, I recommend you contact Katadyn to arrange for an upgrade. Although you may return your watermaker to Katadyn for a free factory-installed upgrade, you will probably have to pay the shipping costs. An easier method is to contact Katadyn, tell them the problem, give them the serial number of your watermaker, and have them send you a new shaft, which you can install yourself. For detailed instructions on how to replace the shaft, see the Repairs Video.

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Pressure Relief Valve Upgrade:  Not long after the original PUR Model 40E watermakers began shipping, company engineers decided that there was a design flaw in the pressure relief valve mechanism. The problem was such that the valve might, in some circumstances, cause the intake seawater to be relieved before adequate pressure was developed in the pump to produce product water. I had noticed this problem in some troubleshooting I had done among cruisers, although I remained ignorant of its cause for quite some time. The symptoms ranged from outright failure of the watermaker to produce product water, even though thruflow of seawater seemed normal, to simply intermittent failures. In my attempts to diagnose these cases, I discovered that replacing the relief valve assembly would usually eliminate the problem. The company engineers promptly redesigned the pressure relief valve and all later PUR models were manufactured with the new design from a rather early point in the model's history. The improved design was also used in all of the Endurance 40E models of watermakers manufactured by Katadyn.

Old and new Relief Valves

At the present time, this design flaw is mainly of historical interest. All Katadyn units, as well as all but the earliest units from Recovery Engineering, incorporate the redesigned valve. If you happen to own a legacy PUR 40E with the old type valve assembly, and your watermaker has been working O.K., I suggest the old saw:  "If it ain't broke, don't fix it."  Oddly enough, not all, or even most, of the original valves seemed to cause a problem. On the other hand, if you have purchased an old PUR 40E with the original valve installed, and it doesn't produce product water or only does so intermittently, it might be worth your while to contact Katadyn to obtain one of the new type of valve.

Note in the accompanying picture that the new design includes a flange at the end that screws into the pump, whereas the original design does not. This makes it easy to determine which one you have. However, there are a couple of interesting facts worth mentioning about these two valve designs, which have often been a source of confusion among owners.

First, the relief pressure setting for the original valve was determined by how far the valve was screwed into its base on the pump. That pressure setting is critical, and there's no good way to adjust it accurately without a special jig setup which is available only at the factory. Consequently, the watermakers have a label next to the valve stating:  "Factory-set Relief Screw—Do Not Adjust."

This was no problem with the first units manufactured because they used a straight pipe-to-hose barb fitting for the reject hose. Notice that this fitting is installed immediately adjacent to the relief valve mechanism. A damaged fitting could easily be replaced without tampering with the relief valve itself. However, soon after the 40E was introduced, one of the engineers observed that the clearance needed to install the watermaker could be significantly reduced by changing the hose barb fitting to a right-angle configuration. That way the reject hose could be led off parallel to the pump. The original straight fitting required the installer to leave enough space above the watermaker for the hose to lead from the fitting and, typically, make a tight ninety-degree bend. Like many things that look good on paper, the new configuration had a problem—namely, there was no way to remove or replace the new right-angle adapter without first removing the relief valve next to it. That, of course, would involve a problem when the relief valve was later reinstalled:  how could it be screwed back in to adjust the relief pressure correctly?  I know of no foolproof way. The best that can be done is to scribe a mark on the valve where it meets the base, and another mark to reference the 360° orientation. That will allow you to screw the valve in reasonably close to its original position.

The second caveat is, I think, a bit humorous. The redesign of the pressure relief valve eliminated the problem of correct pressure adjustment. The new valve installs by screwing it in until the flange bottoms against the base on the pump. In other words, there is no adjustment! It can be removed and reinstalled with no problem in case the hose barb fitting needs to be changed or replaced. The only problem is that the company has continued to put the "Do Not Adjust" sticker next to the valve assembly. The last I heard, they were still doing so. This has caused numerous cases of confusion among owners who are concerned enough to pay attention to the warning. I've often been asked, "Where's the adjustment? How do I adjust it?" Bottom line: ignore the warning label—there is no adjustment to worry about!

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PUR Owner's Manual Problems:  It's an unfortunate fact of life that most people who purchase a new piece of equipment don't bother to read the owner's manual. In the case of the original manuals that were written for the PUR Endurance line of watermakers, that fact is more of a blessing than a hindrance. The simple fact is:  the original manuals that accompanied the PUR Endurance watermakers were so poorly written as to be almost useless. I routinely tell cruisers (with tongue in cheek) to throw them away rather than be misled or confused. There are so many mistakes, misconceptions, and mis-labelings that an attentive reader will quickly become confused and frustrated—I've seen it happen often enough. As an aside, the reason the manuals were so bad is that they were written by the then product manager for Recovery Engineering, who had virtually no technical knowledge of the products. FYI, that manager is no longer with the company.

Fortunately, the situation has changed. When Katadyn acquired the watermaker business, they needed to reissue the manuals in order to, at a minimum, change the brand name from PUR to Katadyn. By that time, company personnel were very aware of the shortcomings in the original PUR manuals and recognized the need to completely rewrite them. My book on PUR watermakers (see the "Watermaker Book" link on the navigation panel) had been out for several years. The company's customer support staff had been routinely sending it to complaining owners for quite some time; in fact, they were my best customers for the book and purchased the lion's share of both printings. They recognized that it was a much better "manual" than the ones that had shipped with their watermakers. When it came time to issue new manuals, they contracted with me to write them. Given the abysmal quality of the original manuals, I was more than happy to oblige.

The result was a completely rewritten set of manuals for the 40E, 80E and 160E. I labored hard to correct all the errors and misrepresentations. In the process, I also introduced much new material derived from my book. I truly believe that the new manuals are 99% accurate and should  be read by every owner. I hasten to point out that since there are no critical differences between the original PUR models and those manufactured by Katadyn, owners of legacy PUR watermakers should obtain copies of the new manual for their model. Initially, Katadyn made copies of all their manuals available in PDF format for downloading from their website. However, I recently checked their website (April, 2010) and could not find them anymore. That's really too bad. I've provided a copy of the 40E manual on this website. Owners of the other original PUR models should contact Katadyn for copies of the new manuals.

I'm often asked when I will be writing a new edition of my book. Well, I incorporated so much of the critical information from my book into the new manuals, that I couldn't see how a new edition would be a significant improvement on them. The information I've included on this website, I believe, fills that gap in a format that allows me to improve on the presentations in both the manuals and my book. A picture—and especially a video—is worth a thousand words!


Katadyn Watermaker Models and Specifications  You can check out the specifications for Katadyn's line of watermakers by clicking on any of the following links:

Survivor 06   Survivor 35   PowerSurvivor 40E   PowerSurvivor 80E   PowerSurvivor 160E

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