My ge pfs22s1sss is not defrosting, tested temp sensor, heating element,both ok. Evaporator thermistor tested bad, now compressor will not run

Probably low on refridgerant. Time to call a refridgeration engineer in.

either the compressor isn't running due to a faulty PTC overload relay on the compressor body or a bad compressor itself,you can test the compressor with an ohmmeter between the 3 terminals on the side of the compressor PTC is mounted,if its ok then it can be a defrost problem where its not melting the evaporator ice and blocking the cold air flow remove the inner rear wall of the freezer and test the defrost heater located below the evaporator coil as G.E. defrost heaters are notorious for failing,if its ok,then the defrost terminator on top of this coil can be bad(open)to test this component it needs to be below 15 degrees temperature to show good(closed) if ok then the mainboard located in the rear back of the unit can be defective because it controls all the units functions

Hi and welcome to FixYa, I am Kelly. This can be caused by several things but usually when it thaws on a routine basis the automatic defrost bi metal thermostat has failed. Using this model number PSS26MSRCSS and this diagram:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5219887&diagram_id=23192126#d23192126
The failed part would be item 240. It is possible however that the thermistor Item 241 could also cause this symtom.

Make sure to read the information about the Defrost thermostat using the link below. Just note that a defrost thermostat will have continuity anytime the temperature is below 60 deg F.

GE Thermistor testing can be found here:
http://www.appliance-repair-it.com/refrigerator-thermistor.html

These are the 2 most common reasons that the a refrigerator will thaw out on a regular basis. Now there can be things like a problem with the PTC relay or thermal overload on the compressor in the form of loose / hot terminals or a bad relay / overload assy. Lastly and repair of last resort the compressor can be dragging and not starting properly or the rotor occasionally locks.
I believe that if you change out the thermistor and bi-metal thermostat that your defrosting probelm will cease. We usually change them both at the same time because the control board is electronic and under nomal conditions the thermistor controls the defrost cycle. The Bi-metal thermostat is there as a back up to terminate the defrost cycle when the temp at the top of the evaporator reaches 60 Deg F and at that time cycles the compressor to start.

Having said all that... if the defrost heater Item 230 of the first link is not heating up at all; the unit will defrost / thaw to 60 deg F every defrost cycle. Most of them will have Blue and orange wires on them and you read resistance at each end of the glass tube on the terminals. No resistance = an open / failed element.

Thanks for choosing FixYa,
Kelly

During the Automatic defrosting cycle there is a 60 Deg F thermostat on the evaporator that must cycle to terminate the defrost cycle and restart the compressor. If for some reason the defrost heating element is not coming on (failed / open / wire terminal problem) The the unit will just sit not operating until it reaches 60 F in the evaporator section of the freeser compartment. I suspect that you have an Automatic defrost heating element problem. Again that can be from a broken wire / terminal or the element itself has failed. It is possible that the 60 deg F thermostat itself is sticking and not cycling when the temp of the evaporator reaches 60F. It can also be caused by the temperature control that does not complete the circuit and start the unit when the fresh food section reaches cycling temp 34 - 37 deg F.

Your particular unit uses a thermistor and what is listed as a sensor to control the defrost and cycle temp circuits.

Parts list here:

http://www.searspartsdirect.com/partsdirect/part-model/LG-Parts/Refrigerator-Parts/Model-LRFC22750ST/3204/0161000/P0809090/00002?blt=06&prst=&shdMod=

Sensor is Item 903E

I am NOT telling to order anything thing. The only way to find out is to read out the components.

Thanks for choosing FixYa.

Kelly




This requires that the back of the freezer compartment be opened to troubleshoot and repair. Troubleshooting is done via resistance checks from the defrost control board or timer to the compressor. Usually blue wire from the control to the orange wire on the compressor then finding out which component has failed by reading resistance before and after each component.

The only way to find out is to use a meter.

Thanks for choosing FixYa.

Kelly

The # 4 thermistor is bad . This tells the main control board , the temp of the coils , if they need defrosted , when they are thru defrosting . This thermistor is the 1 " long , torpedo looking piece , clipped on the top left of the coils , with 2 white wires going to it . Part number WR55X10025 .

Door left open or temp is too warm. most I found is heavy ice build up on freezer evaporator, very easy to tell, pull out one of the drawer and look on the back wall, it should not have any ice on it (a little frost is OK). It may be bad Evaporator sensor, Evaporator fan motor is not running, door evaporator fan reed switch installed upside down,bad connection on defrost heater connector, bad defrost heater element, open heater HI limit switch, open gap on door gasket and compressor never stop running. If no ice build up and compressor is running but temp is rising then it may be sealed system problem. Good Luck.

5 reasons for fridge and/or freezer getting warm: 1- the evaporator coils are icing up and won?t let air circulate. 2- the evaporator fan is not working to circulate air. 3- there is no refrigerant in the system. 4- no power to fridge or compressor. 5- the condenser coils have no air circulation check under the fridge behind the vent. if it is too dusty or the fan isn?t working, it is not getting enough airflow to cool down. replace fan and/or vacuum out the dust. if there is no power to the fridge, the light will be off. if the compressor is not running, there is a defrost timer that cuts the power temporarily to the compressor to melt ice on the coils. it?s located under the fridge behind the bottom vent. If the timer is off and the compressor is not going, the compressor or the main board is bad and needs replacing. there is also a temperature sensor on the evaporator coils that tells the defrost coil to turn on and when to turn off. if the defrost timer is on but the coil is not heating up, replace the sensor. if it still won?t heat up, it?s the timer or the coil. the easiest way to tell if there is no refrigerant- the freezer wall is warm and the compressor is loud. if there is no refrigerant, it may be more cost effective to replace the fridge. if you feel no air coming from the freezer vent, the fan needs replacing. If you feel air moving in the freezer but not the fridge, the channel from freezer to fridge is blocked. if the freezer has air and the rear freezer wall has frost on it, the evaporator coils are iced up and need defrosting. causes: 1. low refrigerant 2. no fan 3. too much humid air in fridge/freezer due to door open or bad door seals 4. the condensate drain tube is clogged 5. defrost cycle not functioning properly if the seal around the door is ripped or not completely sealing, or there is condensation at the bottom or the walls of the fridge, replace the seal(s). no air, no fan. Replace if the refrigerant is low, it just needs a top off. but you need to be certified by the epa to move refrigerant, so get a professional. there defrost cycle starts with the timer. at a certain time of day for a specific time, the timer turns the compressor off and turns on the heater element located at the bottom of the evaporator coil. this stays on until the coil temp sensor reaches a certain temperature to let the timer know that the coils are defrosted and turns off the power to the element. the defrosted water drains to the condensate pan. if the timer is bad, it will never go into defrost, or never get out of it. if the element is bad, the coils will never defrost. if the temp sensor is bad, it?ll go into defrost, but it will either tell the timer that it?s always frozen or already defrosted, resulting in the element never turning on (stays frosted) or never turning off (eventually burning out the element). defrost solutions: unplug the fridge. remove the wall of the freezer that is frosted/icing up. use a hair dryer to melt the ice. do not get too close. you will see a drain under the evaporator coil. make sure it is not blocked. the water should run freely to a condensate pan under the fridge that evaporates the condensation with the hot line from the compressor. once the coil is free of ice, frost, and water, replace the panel and repair any of the problems that caused the icing up. plug the fridge in and turn it on. If it frosts up within a week, there is still an issue that not been taken care of.

In my GE side-by-side there is a defrost temp sensor located near the top of the evaporator coil. I think the control board uses that temp sensor to know when it should be done defrosting.

On the schematic of my fridge (link below), the defrost thermistor is part number 240 in the diagram (not part number 241, which is a different temp sensor located adjacent to the one you want)

http://www.partselect.com/ModelFrames.aspx?ModelID=361233&ModelNum=GSS20IEMDWW&mfgModelNum=&ManufactureID=2&Selected=00113321i06&Position=2&mfg=GE&Type=&Mark=2

I don't know why the defrost element would fail immediately other than incorrect supply voltage or just a bad defrost element.

CODE INDICATION
05 Refrig. Cabinet Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s
06 Refrig. Evaporator Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s
07 Freezer Cabinet Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s
08 Freezer Evaporator Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temp’s
20 Defrost Under-heat with No Voltage Feedback Through Gray/White Wire at Defrost Start
21 Defrost Overheat
22 No Voltage Feedback Through Gray/White Wire at Defrost Start
23 Defrost Overheat with No Voltage Feedback through Gray/White Wire at Defrost Start
24 Defrost Under-heat
30 Excessive Icemaker Water Valve Solenoid Activation (Exceeded 15 Seconds)
40 Excessive Freezer Compressor Run
50 Excessive Refrigerator Compressor Run

I might first suspect the defrost bi-metal thermostat located in the freezer compartment behind the interior panel. It's clipped onto the coils and is usually a little round disk with a couple wires coming out of it. The reason I susupect it is that little device is what "opens" to kill power to the heater once the temps get hot enough to have finished melting the ice on the coils. If that is stuck "closed" or opens WAY out of it's heat range then the heat element will stay on way too long. Next is the actual defrost timer which can be a clock type timer or a circuit board. If you go to this site use GSS22JEM for the model number. Item 240 is the bi-metal, 241 is the thermistor sensor. http://www.partselect.com/Schematics/GE/00113124i06.gif Item 801 is the control board. http://www.partselect.com/Schematics/GE/00113123i02.gif