Case of the Month: A Washing Machine Overflow

Oct 1, 2014 by

The homeowners’ washing machine overflowed. Fortunately, they heard the water splashing, so they quickly stopped the motor and shut off the water before major damage was done. When they finished mopping up the water from the laundry room floor, they called a local appliance repair shop. The shop sent out a technician who examined the washing machine. He discovered that the tub water level sensing hose was disconnected, and he showed this to the homeowner. Then he reconnected the hose, and they watched as the machine did a test cycle with no further leaking.

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The following week the homeowners ran several more loads of laundry without incident. During a later deposition, the homeowner said that there were no unusual loads or conditions that might have been out of the ordinary during that week. He also estimated that they bought the washer 12 to 14 years earlier and that there had been no service or maintenance performed prior to the first leak. Then on Friday evening, they started another load of laundry and went out to the backyard. After 30 to 45 minutes one of them went back into the house to discover water flooding not just the laundry room, but the entire home. Again, the source of the water was the washing machine. They shut off the machine, turned off the water, and began calling contractors and their insurance company. Thus began a several-week process of drying out their home and replacing their hardwood and carpeted floors. They also called the appliance repair company, who was unable to send anyone out until the following Monday. The same technician returned to examine the washing machine. He observed at that time that the level control hose was still attached. At that point, the homeowner expressed that he was ready to buy a new washing machine, and the technician made no further adjustments or repairs. The insurance company kept the washer for later analysis.

After three years of insurance and legal negotiations, GEI was assigned to examine and test the washing machine and to determine the cause of the flooding. Our expert inspected and tested the machine at an independent lab. A representative of the manufacturer was also present. He connected the machine to a domestic hot and cold water supply, a drain, and 120 VAC. He operated the machine through the completion of the fill cycle and measured the water fill level for all water level settings. The machine operated normally. He opened the top cover and inspected the water level control components. He found a very short ½ inch piece of hose in the bottom of the machine. This matched the hose that connected the pressure switch to the tank dome. This indicated that the end of the hose was sniped off by the technician to create a better connection when he reconnected the hose. This was a good thing to do because, over the years, plastic hose ends become deformed from the clamps and the widening force of the nipple.

 

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The hose still had sufficient length. The routing of the hose was altered in that it no longer passed through a binding ring on the washer exterior. This was also a good thing to do because the binding ring could potentially exert a force that could pull off the hose. The hose was clear, so you could see inside of it. It was clear and clean. The tank dome was an air chamber on the side of the tank that connected the pressure sensing hose to the tank internal water pressure. It was semi-transparent. It appeared clean and free of debris. It was clearly not blocked because the machine filled to the proper levels in the tests.

Our expert was unable to duplicate the overflow issue in the lab. The overflows occurred at the home, so the home must have experienced one or more changing conditions. One possible cause of this intermittent overfill problem was a combination of low house water pressure and a weak fill valve spring or sticky fill valve. By design, water pressure is used to close the valve. Irrigation sprinklers can drastically lower water pressure, and this would be intermittent. Another possibility was the manual valve that supplied water to the washer was not fully opened. This restriction would cause a low-pressure problem and could be intermittent because it was reopened each time the washer was used. The fill valve required a minimum of 20 psi to close properly. If the fill valve had a weak spring or internal friction, this minimum required pressure is likely higher. Our expert doubted if debris caused a sticky inlet valve because the inlet screen to the valve was completely clean. Another possible cause was an interment blockage in the tank dome which was now clear. It may have been possible for soap, lint, or waterproof fabric to block the orifice, and then clear itself later when the tank emptied and dried out.

The first appliance service tag stated that the level sensing hose was found disconnected and was reconnected. The expert’s inspection revealed evidence that supported this. A disconnected hose would cause the washer to overflow. The technician tested the washer following his repair, and it operated normally, as it continued to do the following week. The repair done by the appliance technician could not have caused the second flooding event that caused the flooding damage.

The cause of the flooding damage was an intermittent failure of a component of the water level control system due to transient debris and/or a low supply water pressure. It was not the appliance technician’s work.

The approximate age of the cause of those damages was at least one year prior to the date of inspection.

 

Expert of the Month: Greg Booth

Mr. Booth is a Registered Mechanical Engineer in the State of California with more than twenty-five years of experience. He holds a Bachelor of Science Degree in Mechanical Engineering, from California State University, San Jose. One part of his employment history is that Mr. Booth was a Gas Engineer with Pacific Gas and Electric Company, San Francisco where he offered technical support to energy conservation auditors and the company’s customer base, did research regarding energy-saving devices and control systems, and was involved with test system operations for HVAC systems. Additional efforts involved underground gas storage and related piping. At GEI his expertise is involved with investigations relating to issues with HVAC and plumbing systems for commercial, industrial, and institutional facilities, energy-saving systems and devices, cogeneration systems, product liability and code compliance matters.

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