CAUSE & ORIGIN INVESTIGATIONS: HOT WATER TANK AND WASHING MACHINE FAILURES

CAUSE & ORIGIN INVESTIGATIONS:  HOT WATER TANK AND WASHING MACHINE FAILURES

https://sites.google.com/site/metropolitanforensics/cause-origin-investigations-hot-water-tank-and-washing-machine-failures

According to nationwide analyses by insurers, one out of every ten water-damage claims can be traced back to a failed hot water tank or washing machine.  These studies revealed that water heaters or washing machines fail most often when they develop a slow leak or burst.  Most of the time the failure will occur once the water heater has reached its life expectancy, typically suggested by the warranty period of the manufacturer.  If the hot water tank reaches its warranty period, then the insured must monitor the equipment very carefully for signs of leaks or corrosion.  The washing machines fail at least 55 percent of the time due a bursting hose.

Figure 1: Failed hot water tank.  Note the significant corrosion of the exterior shell of the tank.  It should have been replaced several years ago prior to the failure.

The good news is that there are plenty of stress signs that these equipment give prior to the failure.  Proper maintenance, including inspecting the water heater’s anode rod and flushing sediment from the tank, can delay the need to replace a water heater.

  

Figure 2.  Another failed tank that resulted in significant property damage.  The property loss could have been prevented, should the insured have taken an earlier action to properly maintain, repair or replace the tank, because the first signs of rust appeared well before the tank failed.

Most water heater storage tanks are constructed of steel and contain an internal glass lining to protect the storage tank from corrosion.  The glass lining often has imperfections that develop during manufacturing or while handling the water heater during installation. These imperfections allow water to penetrate the glass lining and eventually lead to corrosion of the exterior shell of the storage tank.  If the corrosion persists, the water tank will begin to leak and eventually burst.  Even the tanks that have plastic linings can fail because the O-rings or gaskets (i.e., the joints) can fail over time.

It is also important to note that the sacrificial anodes that manufacturers place in the tanks have a limited life.   Once this metal rod has been “consumed” or “sacrificed”, it can no longer protect the steel tank.  The anode rod should be inspected once every two years and at least annually once the warranty has expired.  Acidic water (low pH) or the use of a water softener that adds sodium to the water making it more corrosive can accelerate the corrosion of the anode rod.  Therefore, it is strongly recommended to more frequently inspect the anode under these conditions.

Preventive water heater maintenance should also include removing sediment by flushing the tank every six months or more frequently if well water is being used that has lots of iron in it.  Areas with hard water, such as the Northeast, will also see faster accumulation of deposits inside the tanks.  As the layer of sediment thickens, it can act as a barrier to the operation of the anode.  In gas water heaters, it can also cause the water heater flame to work harder to heat the water, resulting in early deterioration and deformity at the base of the water heater.  

The pressure relief valve is another weak area that requires carefully monitoring, at least once a year.  At least every five years the valve should be replaced.  If the relief valve is not working properly, heat and pressure can build up and cause the water tank to explode or to prematurely fail.  See Figures 3 and 4 for a tank that failed because the relief valve was not functioning due to lack of maintenance. 

Figure 3.  Failed hot water tank.  Due to lack of sediment removal over ten years or so, and due to clogged pressure relief valve, the tank finally gave in, causing very significant property damage.

Figure 4.  Property damage in excess of $100K caused by the failure of the tank depicted in Figure 3. 

Of all water damage claims related to washing machines, more than half are from water supply hoses that leaked or burst.  Over time, most washing machine hoses, even those that are installed properly, will eventually fail, leading to leaks or catastrophic floods caused when the hoses burst.  Failure may be caused any of several factors, including age, installation error, poor-quality materials, and poor design. 

All washer hoses, whether reinforced rubber or braided steel, must be installed properly, inspected regularly, and replaced before they wear out.  If an inspection reveals any danger signs (such as blisters, bulges, bubbles, cracks, crimps, kinks, unraveling, rust, discoloration, etc.), or if leaks are present, replace the hoses and fittings immediately.  Remember that damage and deterioration may exist on the inside of the hose or fitting and may not be visible during an inspection.

Figure 5.  Bubbles in the water hoses.

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