DEFROST TIMER ! I Have a Whirlpool (model # WRF560SMYB01) that's about 3 years old. French door refrigerator, bottom freezer. It started frosting up on the back panel of the freezer & icing up around the fan making a horrible noise, caused by the ice build up behind it. Took the fan cover off, defrosted it several times with a hair dryer, like every 2-4 days, than I created a system of my own with hot water & tubing which made it faster but didn't fix the problem.... Found the wiring diagram in the bottom part of the refrigerator rolled up in the back that actually has diagnostic instructions to test your compressor, your fans & your heaters to tell you if they are working properly. All controlled by the digital control panel in your refrigerator that allows you to increase or decrease your temperature in your freezer & your fridge, also tells you when to replace your filters & such.... After I found that & figured out the coding of it, I was able to manually defrost my freezer without pulling it out away from the wall & making a big mess with the water & tubing! I figured out it was my defrost timer because I could manually put it in defrost from the control panel in the refrigerator but it wouldn't go into defrost by itself. After that it was a matter of finding the defrost timer on the refrigerator, which I was unable to find anywhere online....So, That's why I'm here now to tell you that your Defrost timer is located in the back, bottom part of your refrigerator on the left hand side, in a white box attached to the side by a metal plate. Unscrew the metal plate pull out the entire box. (You can take the plate off , I did) There are 4 screws, remove the top of that box, inside there is a control board & it controls the defrost system, Which I just replaced & it took about 10minutes after I got the new control board. The problem would be to find a company that will sell you the control board without having any kind of license. We used to have a company called Johnstown? that would sell us parts but now for some reason, they will, but it's twice as expensive if you don't have a license. Found a place called Dey Distributors that will for a reasonable price, but not everyone has one in there area & not everyone knows or will tell you where to go, just because they want you to call a refrigerator repair company so they can charge you an arm & a leg. My Dad was in the Heating/ Cooling
business & I would never think to call someone without looking at it myself first. Unless your Refrigerator needs Freon you can do it yourself for under half of what those guys Charge! They will charge you 60$ just to walk in the door! If I helped just one person fix there refrigerator today that would be GREAT! I was ready to push mine out the door to the curb. Good Luck to all of you!