22 cu ft. bottom freezer has defrost problem,replaced cotrol board,and defrost terminator,heater ohms out good still frosting up.Help!!!

It is a defrost problem. Either the defrost timer is not working or the defrost heater is shorted out. You will need to ohm out the heater. It should have close to infinite ohms. If "open" then that is your problem.

your thermistors are way out of range even at that temperature you say,put each thermistor in a glass of ice water for 5 minutes,then remove the J1 connector from the main board and check with an ohm meter set on 20k ohm between the thermistors common terminal #5 and the other pin terminals all thermistors tested this way should be about 16k ohms when tested this way,if not replace them

Something in the defrost system has failed. Could be a thermostat, the heater itself or the control board. Additionally, if yours was produced prior to March of 2010 there is an update you can do that will prevent this frosting in the event those parts I mentioned check out OK

Since Kenmore is manufactured by several different manufactures, you should find the model number off the equipment id tag and provide that so I can give you the best advice. It will probably be located beside the vegtable tray in that unit, but not always.

You have a defrost system failure. Your defrost system is made up of the defrost heater, defrost thermostat and defrost timer/control board (newer units have incoorporated the timer onto the control board). You will need an ohm meter to check the heater (if it isn't open - it is good) and the thermostat (low ohm reading normal 28-38 ohms) but the timer is a different story. So you will need to rule out the heater and thermostat before replacing the timer/control board.

Hello Tracy,

Most likely the problem why the freezer work but the refrigerator doesn't is going to be a problem with one of the components of the automatic defrost system....do you see a bunch of frost built up on the back wall of the freezer?? If yes ya do frost build up on the back freezer wall it is a defrost problem.Here is what to check to see why its not automatically defrosting.

DEFROST HEATER ...remove back wall of freezer and you will see a black heater at the bottom of the coil thats frosted up,it looks similar to the bake element in your oven,or in some cases it is going to be a spiraled wires inside of a glass tube. To check it,use a multimeter set to the lowest ohms of resistiance setting and follow and find the wires at the top of that frosted coil,unplug/disconnect those wires and check for continuty with around 5-20 ohms of resistiance. If it has that amount of ohms the heater is good. If your meter display does not change or displays OL the defrost heater is broke and needs to be replaced

DEFROST TERMINATION THERMOSTAT... it's round and has 2 wires and clips to the top of that frosted up coil. IT MUST BE CHECKED WHEN COLD SO BEST TO DO WHEN FROST IS STILL BUILT UP. To check it disconnect the wires on it and check for ZERO ohms of resistiance. As with the heater if the meter display OL or doesnt change,it is the problem
DEFROST TIMER...it is not in the freezer but intstead in the control panel in the ceiling of the refrigerator. It has a center hub on it that can be turned until the fan in the freezer and the compressor cut out..then within 5 minutes of the fan/compressor shuts off the defrost heater should be on. If the heater is on within 5 minutes the defrost timer is the problem...if the defrost heater does not come on it will be either the defrost heater or termination thermostat that will be the problem.

Here is what the parts look like;

DEFROST TERMINATION THERMOSTATDEFROST TIMER

DEFROST HEATER



Good luck,i hope i have been able to help you fix your refrigerator,
GENE

To that defrost heater
set the meter to lowest ohms setting
follow wires that connect to heater up to the top of freezer coil
unplug the 2 wires for the defrost heater/or if on huge plug with all wires in unplug that plug
place meter leads on the the 2 wires for the heater
the meter display should be some where between 5-25 ohms of resistiance

if heater is good it will have contunuty with 5-25 ohms,if bad the meter display either wont change or display OL
if heater check good check defrost thermostat pictured below for ZERO ohms resistiance when cold and frost is built up on freezer coil MUST BE COLD to check. It too should have continuty with ZERO ohms resistiance

If both heater nand defrost thermostat check good the defrost control board will be the problem.

This is what the deforst thermostat looks,yours may be slightly different yet very similar and ina similar place(clipped to top of freezer coil usually on right side)

Hello,
That is going to be a problem with one of the components in the automatic defrost system. It is supposed to automatically defrost. Turning it off overnight to melt it will defiently help. If you are mechinacally inclined here is what to check.

DEFROST HEATER ...remove back wall of freezer and you will see a black heater at the bottom of the coil thats frosted up,it looks similar to the bake element in your oven,or in some cases it is going to be a spiraled wires inside of a glass tube. To check it,use a multimeter set to the lowest ohms of resistiance setting and follow and find the wires at the top of that frosted coil,unplug/disconnect those wires and check for continuty with around 5-20 ohms of resistiance. If it has that amount of ohms the heater is good. If your meter display does not change or displays OL the defrost heater is broke and needs to be replaced

DEFROST TERMINATION THERMOSTAT... it's round and has 2 wires and clips to the top of that frosted up coil. IT MUST BE CHECKED WHEN COLD SO BEST TO DO WHEN FROST IS STILL BUILT UP. To check it disconnect the wires on it and check for ZERO ohms of resistiance. As with the heater if the meter display OL or doesnt change,it is the problem

DEFROST CONTROL...it is hard to check for a semi unskilled person and if the heater or defrost t-stat check good its going to be the problem. It will NOT be in the freezer it could be on back wall or inside the control panel in the refrigerator section.

Good luck,
Gene

It sounds like you have a failure of the automatic defrost system. This system has 3 components

- timer, this device provides power to the compressor for cooling then changes to the defrost mode every 8 - 10 hours and provides power for the heater

- heater, this is located just below the evaporator and clears the frost from the coils

- terminator, this device turns the defrost cycle off and prevents over heating during the defrost cycle.

To test the components locate the timer, it is usually on the back or in front behind the kick panel; it looks like this


The white piece can be turned either by hand or a flat blade screwdriver, turn it clockwise slowly until a positive 'click' is heard. Once you hear this stop and wait, you will be in the defrost cycle, if you open the door after about 5 minutes you should hear the water sizzling on the heater faintly behind the back panel inside the freezer. If you do hear that then the heater and terminator are okay and you need to replace the timer.

If you do not get heat you will need to unload the freezer, and remove the back panel. Behind there is the evaporator and below that is the heater. You will have to test the heater with an ohm meter it should read under 100 ohms.

The terminator is clipped to the top of the evaporator and should read 0 ohms when it is cold.

I

You will need a professional at this point.

It sounds like the defrost timer may be bad,or you might want to ohm out the heater itself. And the only othe part is the terminator witch sounds like you replaced that allready. I would check the heater and if that is good replace the timer itself. Hope this helps