Washing machine failures can create significant damage, exposing insurers and their clients to property damage. These failures often involve a high volume of water and can occur without warning. Through the examination of several hundred washing machines, the DONAN Component Testing Laboratory has identified a statistically significant failure trend in General Electric (GE) washing machines. The amount of water supplied to the tub of the washing machine is controlled by a water valve (solenoid-controlled valve) and pneumatic controls. The washing machine's load selector is a pneumatic pressure switch, which activates and deactivates the water valve. The pressure switch, as its name implies, is actuated by air pressure. As water enters the tub, a device that is essentially an inverted cup begins to trap air. The trapped air becomes pressurized and is forced out of the top of the cup through a tube and routed to a similar connection on the pressure switch. As the water level rises, the pressure in the cup and tube increases. This pressure is transferred to the pressure switch and causes its internal diaphragm to move. The movement of the diaphragm opens an electrical circuit, shutting off the power to the water inlet valves and stopping the inflow of water. If the cup, tubing, pressure switch, or water valve fails, water will continue to flow, and the washing machine will overflow.
GE washing machines often fail as the result of mold or other debris blocking the pressure tubing or associated hose barb, causing the washer to overflow. When mold builds up over the opening within the inverted cup or inside the pressure tubing, it prevents the switch from activating and causes the washing machine to overflow.
The failure is not the result of washing dirty clothing or using an excessive amount of soap. Laboratory testing has shown that the water in the tub does not slosh or splash into the tubing to the height at which the deposits were observed, no matter how much or how little soap is added to the washing machine. The deposits are not the result of debris within the water becoming deposited within the tubing, but rather from deposits forming as the result of vapor contacting the tubing. Vapor is found within the tubing of all washing machines, but, with the rarest of exceptions, only forms blockages in GE washing machines.
Ninety-one percent of GE washing machines received have contained blockage in the pressurized air system. During that same timeframe, less than 1 percent of all Whirlpool/Maytag washing machines exhibited this failure, and no Samsung, LG, Fisher Paykel, or Electrolux brand washing machines with this failure were received. The failure mode is essentially exclusive to GE washing machines.
This exclusivity of the failure to GE brand washing machines indicates that the blockage is not due to using too much soap or cleaning excessively dirty clothes, as all brands of washing machines would then exhibit a similar rate of occurrence of this malfunction. Rather, the blockage builds up in the pressurized air system in GE washers and causes them to overflow due to a defect exclusive to GE washing machines.
DONAN, a family owned company founded in 1947, provides full-service Forensic Engineering and Fire Investigation Services. For over 60 years, Donan Engineering has been providing unbiased answers to their client's complicated questions. Their team of licensed and experienced forensic experts provides investigative services in the fields of engineering investigations, fire and explosion origin & cause, roofing investigations, and component testing. The diversity of their multidisciplinary staff allows them to provide not only a complete service, but a complete service whose conclusions can be successfully and completely supported.
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