WHIRLPOOL S20B RSB21 Side by side fridge freezer As many other Whirlpool owners we now have caught the problem with lights flashing and a clicking sound from the back. I have read that we need to replace som electric elements, but can anyone be more specific about what to replace and where to bye the parts ?

Hi!!

Turn unit off and unplug the power cord from the wall, empty the Freezer and take the Inner Rear Panels Off, the evaporator coil should be covered with ice, lay some towels on the bottom of the freezer, use a Heat Gun or Hairdryer to melt the ice. Make sure the air ducts are also free of ice. Replace freezer panels, reconnect the power cord and turn unit back on. Some times, this will take care of the problem.
This problem is often caused by the defrost heater relay. The defrost heater relay is sticking on rear PCB, not allowing it to complete the defrost cycle, causing ice build up which stops the flow of cold air from the freezer to the fridge, you can remove ice again but after week or so, it'll be back to frozen state and have to defrost again. So the solution is to replace the REAR PCB or if you can solder electronic components, find out which one is the faulty relay and replace it yourself.
A PCB runs for about $70 - $160, a relay costs only a couple of bucks. Find the PCB on the back of the unit and take a picture of it, then click on the following link to check the price of your particular PCB. http://www.repairclinic.com/Whirlpool-Refrigerator-Circuit-Board-Or-Timer-Parts?s=b5a4c13e
Good Luck!! Don't forget to rate this post!!

Hi,
This would be the part that you are reading about...
This is also a site in the UK that sells this part...not sure if you are in the UK,
but it seems as though this particular model number is UK specific.

here is the site

Hopefully this will work for you...

heatman101

The clicking, if coming from the electronic module would be the type on the back about 2/3rds of the way up on the freezer side. Some are in the fridge side inside behind controls.

The model number you gave doesn't match the parts sites. Try here to find another number.
http://www.appliancepartspros.com/modelnumber_locator.aspx