Product review (5 stars): It Works!
When we moved into our home, as part of the deal, we bought the Kenmore refrigerator which seemed to be in pretty good shape.  Well, a few months later, water started dripping into the main compartment, and it was coming from the freezer. I searched the internet to find the cause and found that the drain tube, which drains the water when the freezer defrosts, was blocked with ice. Rather than call a repairman with the resulting expensive repair bill, I unplugged the unit and let it thaw for a day.  That solved the problem for about a year when it started happening again. I, again, repeated my first solution, but this time it only lasted a month.  A further search of the internet suggested this heat probe as a permanent fix.  Well, I purchased it, installed it (not too difficult) and, happily, it really works.  I found that the concept is now incorporated in the newer models to solve that particular design flaw.
  If you feel the installation is a little too much, you can call a repairman - it won't be cheap - and have it done, but you can save a ton of money by doing it yourself.
  A tip: to save time (it took me  about an hour and a half from start to finish), use a hair dryer to melt the ice under the removable freezer floor, and then use a turkey baster to flush boiling water down the drain tube to accelerate melting.