Frigidaire 5303917954 Defrost Thermostat OEM Part

My Frigidaire side by side refrigerator/freezer suffered a catastrophic failure. The symptoms were as follows: 1) Frig not cold 2) No Ice being made in the freezer section 3) Items at the back of the freezer were frozen but items on the door shelves would not freeze. The back of the freezer was cold but the closer you got to the door the warmer it got. After removing everything from the unit I saw that there was substantial ice buildup on back of the freeze, specifically around the vents, suggesting that the problem was with the defroster function. After watching the Appliance part pro videos and looking at the schematic for my Frigidaire I figured that there were three possible problems. 1) The defrost timer. I rotated the timer until I felt a “click” and left it in defrost mode. No defrosting happened. I also put marks on the timer with a sharpie and made sure the clock was turning the timer. All seemed well so I figured this was not the problem. 2) I removed the back of the freezer section to expose the heat exchanger and checked the continuity of the defrost heater element. Found some resistance so that should be OK. 3) That left the bimetal temperature sensor. Upon examination I found that the sensor plastic cap was deformed and not making a good seal. I figured that this allowed moisture to enter the sensor and cause it to fail so I ordered a new one from Appliance Part Pro. I received the new sensor two days after the order and installed it in about 30 minutes. That includes exposing the workings, removing the old sensor, splicing the wires together and installing the new sensor. Everything works great now. I did need to monitor and adjust the settings for both the freezer temp and refrigerator temp over a couple of days but that is to be expected. Side note: I have now repaired my washing machine, my dryer and now my refrigerator through Appliance Parts Pros and in the process saved hundreds, if not thousands, of dollars. Side Note 2: I may have a bit of an advantage here as I spent a number of years troubleshooting and repairing office and industrial equipment. Schematic diagrams and mechanical systems do not intimidate me and I own the needed test equipment. Understand that when machines fail they do not hate you and have no vendetta, they are just broken. If you are intimidated or unsure of your ability you probably have a relative, friend or neighbor that can be of assistance. Offer them a beer and they will be happy to help. Think about it, everyone likes to be asked to show what they can do so the person you ask will be honored that you thought of them when you needed help. Remember that the best way to make or enhance a friendship is not to do them a favor but to ask them to do you a favor.

IMPORTANT: Defrost heater was more difficult to install around the evaporator coils than the APP installation videos show, but it can be installed. See below. FIRST: Unplug the fridge/freezer! I tested the thermostat, mechanical defrost timer, and the defrost heater with a ohmmeter and determined that the heater was bad. NOTE: Thermostat must be cold in order to be tested; otherwise, the switch inside won't close and you won't get a reading from the ohmmeter. Take a can of compressed air, hold it upside down, and spray the thermostat. The propellant escaping from the can will quickly freeze the part for testing. Defrost timer testing is too complicated to describe here; see this video: https://www.youtube.com/watch?v=tPpLl2d0094 Testing the heating element is simply a matter of testing for continuity. Unplug it from the wiring harness and test it while it’s still installed in the freezer. As for the installation of the heating element, APP’s videos all show a “U” shaped heating element that can be slid in between the evaporator coils from the bottom. This was not the case for me because the top 4 inches of the new heating element was bent inward (see part #218657301). I checked with APP support and verified that while the heating element can be bent *slightly*, I decided against trying to straighten out the element completely rather than risk breaking the part. I bent the part just a little by gently pulling apart the legs of the heater, and tried to straighten one of the top bends by only 2 or 3 degrees of angle. When I installed the heating element, I took the straighter of the two legs and fished it up through the right side of the evaporator coil about 6 inches or so until I was past the first bend in the heating element. This is crucial because the bottom of the evaporator coil on the right is closed off by a loop of tubing and the element must be fished through. The left side doesn’t have this problem. Once I got past that point, I was able to slide the element up while rotating the other leg of the element to the left so it could clear the left side of the evaporator coil. I managed to then nest the left leg between the evaporator coils on the left side and then position the heating element into place. Hopefully, this will save someone else the aggravation of trying to figure this out all over again.

After correctly diagnosing the problem, the solution was quite easy. Since the defrost heater was failing, excessive ice was building up, and not allowing cold air past the evaporator coils into the refrigerator. Replacing the defrost heater solved the problem. I like to be sure, so I bench tested the defrost timer (there are several You Tube videos for help with testing the timer), as well as the heater. I also tested the defrost thermostat by putting the thermostat in our basement freezer for 30 minutes and then testing for continuity with a multimeter. Even though the thermostat tested ok, I elected to put a new one in anyway, since it was only another 15 bucks and easily accessible during the heater changout. Reassembled everything and the fridge works great!

First I had to determine why the evaporator coil was freezing up . There are four parts that if any of the four are defective will cause your evaporator coil to freeze up. #1 evaporator fan #2 defrost heater #3 defrost timer and #4 defrost thermostat. With an ohm meter I checked my defrost heater, which checked good . Next I checked my evaporator fan , a simple way to check is to plug in your refrigerator , open the freezer door and listen to hear the fan blowing. My fan was working ok. That meant that either the defrost timer or the defrost thermostat were my problem. Since there is no simple way to check them I replaced both . When your evaporator coil freezes up food in your freezer start thawing, and items in your fridge warming up.

Bought new thermostat and installed it. Even though it did not look the same I was able to figure it out.