3 Adjuster Questions a CTL Should Be Able to Answer

An insurance professional is likely to encounter many claims related to failed components that resulted in further losses, such as a leaking washing machine valve that caused water damage to the flooring. However, they may need more information to determine the circumstances that caused the initial product failure. The adjuster may have questions about how manufacturing practices or the material composition caused the component to fail and the property to sustain losses. The adjusters should be able to turn to a component testing lab (CTL) for answers to the following questions.

1.    Did a manufacturer’s defect cause this part to fail?

Manufacturers have a responsibility to produce and sell quality products, particularly if they could pose a risk to users and users’ property should they fail. However, design or manufacturing mistakes may be made, and defective components may slip through quality control. It’s important to determine if a loss was caused by a manufacturer’s defect rather than age-related deterioration, installation error, misuse, or freezing conditions.

For instance, when a toilet supply line failed and leaked water into the bathroom, the adjuster handling the claim needed to know why. A certified professional engineer in a CTL performed a nondestructive study on the supply line and noted that the coupling nut was fractured all the way around, splitting it into two pieces. 


This coupling nut fractured and split into two pieces, and a thorough examination revealed evidence of the primary cause of failure.

The coupling nut in this claim was made of injection-molded plastic, and markings indicated that the way the plastic had been injected into the mold had left it vulnerable to stress and prone to fracture. 

By submitting the component to a CTL, the adjuster was able to confirm the cause of failure was a manufacturer's defect associated with improper design or improper injection-molding practice.

2. Did the component’s metal composition lead to its failure?

Most manufactured metal components are made from alloys, which are the products of combining two or more metals. Alloys merge the properties of each element to create a substance that’s greater than the sum of its parts. The amount of each element in an alloy determines characteristics like strength, corrosion resistance, and conductivity. However, the composition of the alloy also determines its weaknesses and susceptibility to certain failures. For instance, brass is an alloy primarily consisting of copper and zinc, and the proportions may vary to achieve certain results. Brass containing high concentrations of zinc are susceptible to corrosion by dezincification or stress corrosion cracking (SCC).  

Brass components used in plumbing must follow specific codes and standards to make them more resistant to SCC. Adjusters may need a CTL to determine if a failed brass component met these standards or if the metal composition resulted in the failure. A CTL should have the specialized equipment required to determine the metal composition of alloy.


This brass coupling has become brittle due to corrosion or dezincification and has fractured under the stress. A CTL determined that the manufacturer did not meet the required standards for this component.

3. Why did this appliance ignite a fire?

Gas and electrically powered items like home appliances can be at risk of igniting a fire under certain conditions, including misuse, improper installation, and manufacturer’s defect. Burn patterns, evidence of arcing, and melted plastic components can provide engineers at a CTL the information needed to tell an adjuster how the appliance caused the fire.  

A dryer was determined to be the ignition source for a fire, and the adjuster handling the claim wanted to know how the dryer ignited the fire. A certified professional engineer evaluated the dryer and researched its model and date of manufacture. Research showed that the manufacturer had agreed to settle a class action lawsuit related to the sale of this type of dryer, which was known to cause fires due to lint buildup.

Burn patterns indicated that the fire was ignited by lint contacting the heating element, and then circulating through the drum and into the lint filter. Once there, the lint ignited the filter and surrounding plastic components. The CTL engineer determined this was consistent with the failure described in the class action lawsuit.


The burn patterns and other evidence helped a professional engineer determine how the fire occurred.

Insurance professionals should turn to a component testing lab when they want answers about whether a manufacturer’s defect or installation error caused a loss, if metal composition impacted a component’s function, or how an appliance ignited a fire. Donan’s Component Testing Laboratory operates two full-service facilities designed to answer these questions in a quick, seamless, and hassle-free process. If you have questions about component failures, or if you need to decide your next steps regarding a claim due to component-related losses, submit an assignment to get the answers you need.