Dip tubes failing in water heaters
Pieces that break off the tubes are clogging faucets and reducing water heaters’ operating efficiencies. Dip tubes have been cited as the source of plumbing problems for more than 11,000 water heater owners already.
Plumbing contractors across the country are receiving calls from customers who complain of mysterious white "chips" that float through their plumbing systems and end up getting trapped in dishwasher and clothes washer filters, faucets and showerheads. The plumber then must diagnose the "chip" problem and determine if the plastic dip tube is the source.
Dip tubes are extensions of the cold-water inlet to the water heater and force the cold water to the bottom of the tank to avoid contact with the hot water already occupying most of the tank. The problem is that polypropylene dip tubes are reacting with the hot water by falling apart. The dip tubes deteriorate into chips or a white sludge that sticks to the interiors of water heaters and pipes.
Perfection Corp. in Madison manufactured the tubes between 1993 and 1996. In 1993 Perfection changed its manufacturing process to save money for itself and its customers. Once more than 20 complaints of prematurely failing dip tubes reached Perfection’s offices within two years of manufacture, the decision was made to return to the original formula and abandon the cost-saving method, which occurred in 1996. Normally such a failure takes four years to develop.
By its own estimates, Perfection sold the dip tubes to about 90% of U.S. water heater manufacturers.
Even though the dip tubes in question have not been manufactured for more than two years, the problems they caused still are surfacing. An article in the Jan. 17 Kansas City Star described the problem and drew national attention. Perfection is quick to remind plumbing professionals and the public that the number of dip tubes and water heaters that have failed is very small compared to the number of water heaters sold between 1993 and 1996.
"We have received 11,555 returns up to Jan. 6, which represents 0.07% of the approximately 24 million water heaters potentially affected," said Frank Volgstadt, vice president/ research, codes and standards, Perfection Corp. "We’re talking about parts per million now. It’s a very small percentage of incidents out there. The Battelle Memorial Institute in Columbus, Ohio, did some research and estimated that we’d log a total of 15,000 to 16,000 dip tube failures when all is said and done, so I believe that we’re over the hump with this."
Perfection is not taking the problems lightly, however. The manufacturer was in contact with the U.S. Consumer Product Safety Commission when it first realized the problem could be dangerous. The cpsc did not issue a recall, however.
"We looked at the dip tube issue a while ago and did not find a safety hazard that would warrant further investigation," said Russ Rader, cpsc spokesman. "A safety defect must be discovered for us to act. There is a distinction here between a manufacturing defect and a safety hazard."
A procedure for customers and contractors to follow in faulty dip tube situations has been established by Perfection. The procedure is to handle the situations in the same manner as a warranty case.
"Most of these water heaters are under warranty anyway," Volgstadt said. "So there is nothing special about handling these situations except to diagnose the dip tube as the source of the problems and then to send the old dip tube or water heater back to us for replacement. The water heater manufacturer ships a new water heater or dip tube to the contractor, the water heater manufacturer reimburses the contractor and then we in turn reimburse the manufacturer and take care of them. Eventually we pay for everything. We want to do the right thing in this situation."
Water heater manufacturers want to do the right thing too. Those contacted said they were replacing either the dip tube or the water heater at no charge to the contractor or the homeowner.
The problem with the dip tubes was discovered in 1995 by Dan Hutchins, president of DiHydro Services, a water treatment consulting firm. After years of increasing numbers of dip tube failures, Hutchins wrote an article describing the problem in Opflow, a publication of the American Water Works Association in December 1998.
Hutchins determined the dip tubes had reacted with the hot water, softened and broken away from the water heaters. "With the dip tube broken away, the cold water comes into the top of the tank, creating more turbulence while reducing temperatures and requiring the thermostat to be adjusted upward. The hot water continues to change the structure of the nonmetallic dip tube, causing it to become brittle," the article states.
"If you take a handful of crackers and crush them as much as you can four times and then pour that onto a table, that’s what happens to the dip tube," Hutchins told Contractor. "And that stuff gets into filters and screens and pipe and it’s hard to clean out. Most plumbers have no experience with back flushing, so they take the fixtures out and clean them or even replace them sometimes, which costs the customer lots of money."
The industry had been using copper for years, he explained, and began using plastic for cost issues. Pitting and scaling can occur when using copper so no product is perfect, he added.
The two solutions DiHydro came up with were to replace the dip tube, flush the water heater tank, and flush the strainers and aerators, or to replace the water heater and perform the same flushing techniques. Regardless of which solution is used, Hutchins said, the fixtures, strainers and aerators will have to be cleaned again and again until all of the pieces of tube are flushed from the piping.
Roger Peugeot, president of Roger the Plumber, Shawnee Mills, Mo., said homeowners may be reimbursed for a new water heater, but that only takes care of half the solution. Distribution piping still needs to be flushed completely so all remaining pieces of pipe are removed, and that costs money.
"We are in contact with A.O. Smith because most of the heaters we install are theirs," Peugeot said. "They have taken care of the problems that are under warranty. We clean out the water heater if we can, or if it’s in a finished space we’ll pull it out and replace it. There has not been a case where the customer had to pay to fix the problem out of his pocket."
"If the unit is not A.O. Smith, we have a fee of $395 to change out a heater including cleaning out the pipes. The particles go through the plumbing systems and get stuck in places like pressure balancing valves, and it takes hours to clean one of those out. The particles also build up in solenoid valves in dishwashers and clothes washers. Even with a new heater you could still have gunk in your pipes. And if you don’t clean out the pipes you could still have ‘chip’ problems."
Peugeot’s business performed 26 dip tube remedies in five days, and not one of the customers had heard about the problem, he said.
"It’s a major problem if the manufacturers don’t let the public know about it. We received 38 calls on Sunday (the day of the Kansas City Star article) and 211 calls in four days regarding this problem."
Not every customer who calls with complaints of low pressure or not enough hot water has a problem with a dip tube, said Herb Foster, director/consumer affairs, Bradford White. The dip tube is not the only factor that can lead to the symptoms found in these situations. An incorrectly set thermostat, a faulty thermostat or other non-plastic sediments in the tank could cause a decrease in the temperature of the water.
All of Bradford White’s dip tube issues have been remedied successfully thus far, he said. Once a dip tube situation is resolved any service charges have been passed along to Perfection, which has paid them, provided the charges are within reason.
A.O. Smith is handling the dip tube situation in a similar manner, said Ed O’Connor, vice president/human resources and public affairs, A.O. Smith. First the plumbing contractor must ascertain that the dip tube is the problem. Then A.O. Smith personnel walk the customers through the process of fixing the problem. If everything checks out A.O. Smith passes the bill to Perfection.
"This issue becomes a service issue," O’Connor said. "Wholesalers perform as the middle man as they do in warranty situations. Generally the amount it has taken to fix the problem has been about $160 to $170, depending on the area of the country."
"The problem with the dip tubes covers our residential products across the board. We made about 3 million water heaters during the years 1993 through 1996. We’ve had about 1,000 complaints involving dip tubes as a result, which isn’t that many compared to the total number sold," he said.
Not every water heater manufacturer used Perfection dip tubes in its manufacturing process. State Industries said it used dip tubes made by one of its subsidiaries. State is limited to what it can say about other manufacturers’ products, but still stands behind its own.
"State Industries believes that it does not have a significant problem in the area of dip tubes," said John O’Reilly, creative director, Loran Nordgren & Co., State Industries’ marketing agency. "The vast majority of dip tubes used in State’s water heaters were manufactured by Apcom, which is a subsidiary of State. Apcom’s dip tubes are made of pex, which is a different material than what is used in other dip tubes."
Both Bradford White and A.O. Smith told Contractor they have no plans to switch their dip tube suppliers. "We have triple checked Perfection’s latest tubes and they are to the right standards," Bradford White’s Foster said.
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