Bimetal Defrost Thermostat

I troubleshot the problem by reading the electrical schematic and concluding the heating elements (defrost cables) were either defective or the bi-metal temp sensor was open. When closed the temp sensor completes the circuit for the current to flow through the heaters to defrost the cooling coils every 8 hours and then when the bimetal opens at 55 degrees the circuit is open and the coils are cooled because the refridgeration motor is in run mode. A timer between the motor and heater elements also was defective. The timer controls the cooling period and the defrost period. I ohmed out each part according to the spec sheet of normal resistance of parts and thus the bimetal and timer were defective. I gather a surge of some duration and amplitude affected these parts because a storm 24 hours prior to refridgerator problem had passsed through the area and the AC electrical power had oscillated several times during that event. I used hand tools to do the repair. If you are not mechanically inclined a step by step proceedure would be moot. It is a matter of disassembly and assembly paying close attention to fragile parts.

A. remove food from freezer and store in cooler etc.
B. turn off frig with dial in main compartment, then pull frig out away from wall and unplug and remove the cover ( It is located at the bottom of the frig and may be cardboard and contains a handfull of 1/4" screws) exposing the compressor and drain tube (this is a good time to vacume the compressor and coil area)
c. Take false back off from freezer by removing two 1/4 inch screws.
Next,
1. we made sure that the drain tube that runs down to a drain pan near the evaporator coil was clear, we did this by using a small aount of rock salt to speed up the melting of the ice then poured small amounts of hot water (boiling into the drain hole and soon the water flowed down the tube and into the pan below.
2. We then pushed a #12 standed electrical wire (with its end stripped back 1-1/2" then folding the strands back to create a broom) down the tube to the pan to push out any debree that may be present i.e. tin foil plastic bag particles, food chunks etc.
Making sure that this drain tube is clear is the first thing that could be causing the ice build up and water in the lower compartment!
However, I performed this several times and didn't change the problem so I chose to change the parts associated with defrost:
1. defrost heater, which is very easy to change. it is mostly plug and play but does require a pair of needle nose pliers to open a couple of metal fins to remove heater from its mounts, just be gentle with the process.

2. defrost thermostat, which is also very easy to change (Simply pull it off of a copper tube) but requires you to cut two wires near the old part and wire nut the new part wires to the remaining original wires, I added some anti oxident to the wires inside the wire nut to prevent a bad connection from developing do to moisture in this area (You can buy wire nuts with this already inside them, do this)and I taped the wire nut with a few inches of ELECTRICAL TAPE CLOSING OFF THE OPENING OF THE WIRE NUT.
You can then put his cabinet back together!
3. I also decided to change the defrost timer which is located inside a cover where the frig temperture setting dial is located. It is held to this cover by two phillips screws the cover is held in place by one 1/4" screw.
once you have the cover off and the defrost timer unscrewed you must remove a plug from the timer!
Now if you got the exact part you simply reinstall the defrost timer plug in the same postion on the new timer and screw the timer back onto its mount etc. However you may need to determine if the new timer is in the "DEFROST" position and you will need to take it out of that position by I assume rotating the timer mechanism (Ask a tech person about this)!!!!!!!!!
Then with all that done plug your frig vack in reposition it turn it on and be proud of yourself.

Now, if you recieved the timer I did it may look the same as the old one, but it may contain a black wire!!!
You will need to know which type of defrost timer application you frig uses:
1. Continuous run
2. version 1 Cumulative compressor run.
or
3. version 2 Cumulative compressor run.
I found a wiring diagram folded up and stored in the grill in the bottom of the front of the frig that helped me determine this. you will need to be able to read a wiring diagram but I found this situation to be simply a matter of matching examples of pictures (line diagrams). It is important though as you must determine which timer application your frig has because the black wire must be placed on a certain terminal for proper operation.

I replaced a three parts and may have, through trouble shooting, been able to save some money by not replacing all these parts. However , I found that when I went for guidance on trouble shooting that i.e. with the heater that ohmic values of the old part may be near the new part that it may still not be conclusive!? so for a hundred bucks my frig may last 5-10

first I diagnosed the problem with the whirlpool do-it-yourself repair manual, which was very easy to understand. as per the repair manual, "this part located on the evaporator or the back of the liner is used during the defrost cycle. This bimetal senses the temperature from the evaporator. When the temperature reaches 50-70 degrees (F) the defrost bimetal turnd the defrost heater off. " then I emptied the freezer. removed the the back panel to expose the evaporator. I looked for the bimetal defrost thermostat clipped on the evaporator. tested the bi-metal defrost thermostat, as per the manual, " the ohmmeter should show ZERO resistance (continuity). if not, the bimetal is bad and needs replacing." NOTE: the bimetal must be cold. it is also tested with the bimetal warm/hot, by running it under hot water. i used a styrofoam cup with hot water & dipped the bimetal in. as per the manual, " the ohmmeter should show an open circuit. if not, the bimetal is bad and needs replacing. then got online found partselect.com. ordered the part, recieved it in less than 2 days. within minutes after recieving the part, I removed the bimetal defrost thermostat and spliced in the new one. thanks to partselect.com my fridge is back up and running properly again. prior to installing the new bimetal, i tested it, as descibed above, you can hear & feel the bimetal open/close when it gets hot/cold.

Repair went fine, no problems, had to wait for fan and compressor to come on. New defrost timer must of been in defrost mode, came on in about 30 minutes and is working fine, should get a few more years out of it.

I first disconnected the power cord and then removed all the panels and disconnected the Defrost Heater at the quick-disconnect, and cut the wires on the Defrost Themostat. (The Defrost Thermostat had been replaced about 10 years ago when the Defrost Heater was replaced.) One of the reasons it took longer than 15 minutes was because there was a buildup of ice in the freezer section. I then soldered the wires and covered them with a plastic sleeve and wrapped them in electrical tape. After replacing all the panels and re-connecting the power cord, I restarted the refrigerator. After one week, there is no water dripping from the freezer and everything is working properly. Your diagnosis of the problem was exactly right. Thanks for the info.

After noticing my freezer was ice cold and the refrigerator was luke warm, I figured there was an airflow problem due to either a fan that failed or the evaporator coil iced over. Just by opening the freezer door I could hear the fan blowing so it had to be the evap coil. Sure enough after removing a couple screws and the back panel I saw the ice. I then unplugged the frige to let it thaw overnight. In the morning I inspected the coil and luckily noticed right away that this little piece didn't look right. The top of the bi-metal thermostat was raised up. Almost like it popped. I read the other reviews on this website reffering to using an ohm meter to see if it held continuity. Well it didn't because the piece really did "pop". The wire was severed. So the ohm reader read open even if the piece was warm. I ordered the part and in days was able to replace the part. NOTE TO BUYER. It did not come with electrical connecting nuts or whatever they are called. So you'll have to go to the hardware store and pick some up for about $2. Frige works fine now. Thanks parts select.

first thanks to part select for the info in the web site.last week notice the area in the refrigerator.was bearly cold. went to parts select read the coments.and whala.i am an expert.my wife was amazed.i was sure the evaporator fan not work,but reading in the web site i learn it can be few other parts so a change all 3 parts,just to make sure, thank you again part selact you are the best.and thank you for the magazines.. JOSE ANGEL

Basically, I read all of the remarks from other people that had the same problem , I replaced both the timer and thr defrost(bi metal) thermostat as the thermostat had a ohmic value when closed that I was not comfortable with. The unit is now up and running and defrosting as it's supposed to do. I could not get those pushdown clips that hold the timer unit , I ended up breaking them off at the plastic post but there was enough of the plastic post showing that a bit of hotmelt glue was able to hold the timer secure.

First, unplugged the refrigerator. Then removed bottom plastic liner of the freezer, 2 screws with 5/16 nut driver. At this point the ice maker had to be removed 3 screws, two on the upper part and the other under the ice maker. Now the back wall of the freezer section was removed by unscrewing 2 screws with the nut driver. This gave me access to remove the defective clip-on Bimetal defrost thermostat. It was located in the upper right corner on the back wall of the freezer. Cut off the 2 wires from the bad part( one pink the other brown)then used wire nut to replace with the new part and matched wires from freezer to new part( pink to pink and brown to brown) and clipped the part in one section of the coil. ( where the bad part was located) Put all back in place. And so far no more water leak inside the fridge.

I deenergized the refigerator, removed the storage tray, three screws that hold the ice maker, two screws that hold the lower portion of the freezer, two screws tjhat hold the back portion of the freezer. Removed the ice maker and disconnected the wire connector and ground, Removed lower portion of the freezer which allowed the back portion to be lifted out. Once the back was out the bimetal defrost thermostat was located in the upper right corner clipped to a copper line. Using an ohm meter, I found the bimetal defrost thermostat to be electrically open, ordered part from information found on part, Once part arrived I deenergized the refrigerator and replaced bimetal thermostat by cutting the old thermostat wires (pink and brown), stripping the wires back about 5/8 inch and wire nutting the replacement parts like colored wires, clipped the bimetal part on the copper tube, replaced the covers in reverse order, and reenergized the refrigerator. Testing and replacing the part took about 15 minutes, waiting for the ice build up to thaw took considerably longer.