Westinghouse 522 frost free fridge not switching off on thermostat

Either the thermostat is failing to switch on the defrost panel at the end of each cooling cycle or the defrost panel has failed...

Try this link to a similar problem of replacing them.

How to replace light bulb in my Westinghouse Silhouette 522 Fridge

http://www.fixya.com/support/t15051109-replace_light_bulb_in_westinghouse

There is a few models of refrigerators that in order to reset the thermostat control, all you have to do is unplug the main power plug for 15 seconds and plug it back in. If this does not work on your model, you will probably have to get another thermostat card. If your model is still under warranty, call the 800 toll free number and pay the nominal service fee and get an authorized repair man. The parts should be free if still under warranty.
Hope this helps

I've been on fridges where this happened. I've found the thermostat to be the issue, or the temp sensor to be the issue. It's hard to check without being there with the proper equipment. It may be worth the money to contact a service tech. lmk if you need more help!

First of all switch off the fridge and allow all the frost to clear off Then reduce the settings on the thermostat and switch on the fridge. If the fault stays then check if the compressor is shutting off , if not your thermostat can be faulty. Also if the timer is not working then frost can build up and reduce cooling. so check this out before you confirm. Repeat the shut down when the frost develops and do your settings/corrections before switch on. Only then you can confirm on the fault. Hope you try this out. Good day

change the timer

UNPLUGGED FOR 24 HOURS AND LET IT TOTALLY DEFROST.

The heating element, located behind the back plate of the freezer, is probably not working. A failed heating element leads to a build up of ice around the evaporator coils in the rear of the freezer. If the back plate of the freezer is removed (ONLY DO THIS WITH THE APPLIANCE UNPLUGGED FROM THE POWER SUPPLY) and there is a large build up of ice around the evaporator coils then it's a fairly good indication that the heating element is not working. The heating element comes on periodically to defrost/de-ice the evaporator coils. Heating element is often activated by a small timer switch which turns the heater on for a set time every 24 hrs or so. Heating element may be open circuit or timer switch may not be operating. Most likely to be open circuit heating element.

Temperature sensing thermostat could be going bad. Also check to make sure the refrigerator light is shutting off when you close the door. There should be a switch to control the light operation when the door is opened and closed. Operate the switch by pushing it in as if the door was closed and make sure the light goes off each time.

Try contacting the hotline again and ask them if the freezer has a frost sensor on it. If it does, the sensor is not kicking the thermostat to allow for the unit to defrost.