Originally Posted by
frankc
Hi
I know this thread is old but I wanted to chime in on this tragic issue. I am a retired electronic engineer of some 40 years. I'll bet without a doubt what happened was one of two things. First the heating wire coils shorted for one reason or an other, BUT my real guess without seeing and being able to examine the pad is there is a component in the heating control called a thermistor. It's job is to send a signal to the control and tell it to shut down or start up depending on were the temperature is set. These thermistors are used in all kinds of appliances for various reasons but usually temperature control. Most manufactures use cheap electronic parts to save money of course. These pads like all electronic appliances are supposed to be UL approved and tested,however not all are they do a sample testing by submitted units from the manufacture. When a thermistor fails it will do one o two things depending on the failure, the unit depending on circuit design will just stop working OR will let in this case the temperature to run uncontrolled. My suggestion in buying a heating pad is DON"T believe all the advertisements that we are the best. Pick a few, check the UL website to see if they really are UL approved, also ask around and see who is using what kind of pad and what there experience has been with it. This is still not a 100% guarantee because all electronic components will fail with use and age at some time. But check and see if the pad in question also has a fail safe, meaning in the event of component failure the unit will shut off.
I am so sorry this happened to you and those poor babies, and I hope by explaining the causes of your tragic event helps some and gives more people more info on what to look for.