How do you gain access to the thermostat and defrost element

DEFROST PROBLEM
The evaporator coil behind the cover on the back wall inside the freezer will ice up under normal conditions. Every 8 to 10 hours for around 20 minutes the defrost timer (or in most newer models the electronic adaptive defrost control) will turn the defrost heater on to melt the built up ice. There is a defrost thermostat which prevents the heater from overheating the freezer by breaking the heater circuit when the temp reaches close to 32 degrees F. The entire cooling system shuts off during the defrost cycle and starts back when the timer advances through the cycle.

If this ice is not melted it will continue to build up until the air can't flow over the coil to circulate the cold air through the freezer and into the fridge. The temperature change in the fridge is usually noticed first followed by the freezer.

If the defrost thermostat is bad, it can prevent the heater from coming on OR it won't turn the heater off when it gets too warm. It is clamped to the evaporator coil at the top to sense the temp. If it appears to be misshapen it is bad.
With an ohm meter it should show continuity when cold and none when warm.
You can also bypass(disconnect the two wires plugged into it and twist them together) the thermostat to see if the heater comes on then. If it does then you know the thermostat is bad and needs replaced.

The defrost heater is located on the evaporator. It is in a tube which is at the bottom and can also go up the sides of the evaporator. On some types you can see a burnt spot if it's bad. With an ohm meter it should show continuity from end to end when disconnected from the wiring in the freezer. You can also test the wiring for voltage when it's in the defrost mode.

If you have a defrost timer you can test it. It can be located under the fridge behind the kick panel on the front. Some are in the fridge with the controls at the top. You can turn the defrost timer till it clicks and everything shuts down. The heater should now come on. If it does, replace the timer because that means the timer is not running. If it doesn't, check the heater and defrost thermostat. Turn the timer again till everything starts back up to end the defrost cycle.

If you have an adaptive defrost control instead of a timer, replace it if the heater and thermostat test good. It is located in the fridge with the controls in some models and on the back in others.

ic Defrost Thermostat
This is the component that controls how long the heater stays on when the machine is in defrost mode. Say the defrost cycle is thirty minutes, the heater may only be on for ten of those thirty minutes on the timer controls. On Adaptive Defrost Controls, when the heater shuts off, shortly after the machine exits defrost mode. Basically if the heater only stays on for ten minutes, the whole defrost cycle will only be about 12 or 13 minutes longe is continueing to build up due to one of the defrost cycle parts not fucntioning properly this is the most likely piece to be causing your ice up issue do a continuity test on the thermostat to assure that it is working properly
Basically when the heater comes on, it starts to melt the frost on the evaporator. Once all the ice and frost is gone, the temperature behind the panel will start to rise. Once the temperature behind the panel rises to a certain temperature, the thermostat will break the current of electricity going to the heater. Bam, it shuts off and prevents your freezer from becoming a sauna, or an oven. I'm sure you get the drift. The heater is on the bottom of the evaporator coils and the defrost thermostat sits on top of the evaporator coils.
Defrost Heater
This is the last component in the defrost system. This one should be pretty simple. By now if you have read this far you should already know what this does and how important is it. Some defrost heaters are a coil of wire in a glass tube under the evaporator coils. Works like a light bulb basically. The other style looks like the bake element in your stove. They both get red hot either way and melt the frost
Defrost control or timer. Some refrigerators have a defrost timer. This type works like a clock. Every eight hours or so the machine hits the defrost spot and that's when defrost occurs

Some refrigerators have an Adaptive Defrost Control. This is what makes a refrigerator energy efficient. It varys the length of time it takes the machine to go into defrost. So instead of the energy hogging heater coming on every eight hours, it may be 24 hours, 18 hours, 10.5 hours, who knows. It depends on how many times you have opened the doors, how long the compressor has run. This is good because the refrigerator may not need to go into defrost every eight hours. Now you are saving energy.

and lastly there is the fan also if it is not working will not allow the flow of air to leave the inside of the freezer. Continuity test can also be done on the heater as well and the least likely would be the timer to go bad in some models they have a board on the back of the machine instead of a defrost timer if you have any further questions please message me back and please remember to rank how this opinion has helped as well Thanks again Rick

Melt the iced up evaporator with a hairdryer for a temp. fix. The auto defrost system isn't working. I can't find diagrams of yours but here is basically how it works.

The evaporator coil behind the cover on the back wall inside the freezer will ice up under normal conditions. Every 8 to 10 hours for around 20 minutes the defrost timer (or in most newer models the electronic adaptive defrost control) will turn the defrost heater on to melt the built up ice. There is a defrost thermostat which prevents the heater from overheating the freezer by breaking the heater circuit when the temp reaches close to 32 degrees F. The entire cooling system shuts off during the defrost cycle and starts back when the timer advances through the cycle.

If this ice is not melted it will continue to build up until the air can't flow over the coil to circulate the cold air through the freezer and into the fridge. The temperature change in the fridge is usually noticed first followed by the freezer.

If the defrost thermostat is bad, it can prevent the heater from coming on OR it won't turn the heater off when it gets too warm. It is clamped to the evaporator coil at the top to sense the temp. If it appears to be misshapen it is bad.
With an ohm meter it should show continuity when cold and none when warm.
You can also bypass(disconnect the two wires plugged into it and twist them together) the thermostat to see if the heater comes on then. If it does then you know the thermostat is bad and needs replaced.

The defrost heater is located on the evaporator. It is in a tube which is at the bottom and can also go up the sides of the evaporator. On some types you can see a burnt spot if it's bad. With an ohm meter it should show continuity from end to end when disconnected from the wiring in the freezer. You can also test the wiring for voltage when it's in the defrost mode.

If you have a defrost timer you can test it. It can be located under the fridge behind the kick panel on the front. Some are in the fridge with the controls at the top. You can turn the defrost timer till it clicks and everything shuts down. The heater should now come on. If it does, replace the timer because that means the timer is not running. If it doesn't, check the heater and defrost thermostat. Turn the timer again till everything starts back up to end the defrost cycle.

If you have an adaptive defrost control instead of a timer, replace it if the heater and thermostat test good. It is located in the fridge with the controls in some models and on the back in others.

DEFROST PROBLEM The evaporator coil behind the cover on the back wall inside the freezer will ice up under normal conditions. Every 8 to 10 hours for around 20 minutes the defrost timer (or in most newer models the electronic adaptive defrost control) will turn the defrost heater on to melt the built up ice. There is a defrost thermostat which prevents the heater from overheating the freezer by breaking the heater circuit when the temp reaches close to 32 degrees F. The entire cooling system shuts off during the defrost cycle and starts back when the timer advances through the cycle.
If this ice is not melted it will continue to build up until the air can’t flow over the coil to circulate the cold air through the freezer and into the fridge. The temperature change in the fridge is usually noticed first followed by the freezer.
If the defrost thermostat is bad, it can prevent the heater from coming on OR it won’t turn the heater off when it gets too warm. It is clamped to the evaporator coil at the top to sense the temp. If it appears to be misshapen it is bad. With an ohm meter it should show continuity when cold and none when warm. You can also bypass(disconnect the two wires plugged into it and twist them together) the thermostat to see if the heater comes on then. If it does then you know the thermostat is bad and needs replaced.
The defrost heater is located on the evaporator. It is in a tube which is at the bottom and can also go up the sides of the evaporator. On some types you can see a burnt spot if it’s bad. With an ohm meter it should show continuity from end to end when disconnected from the wiring in the freezer. You can also test the wiring for voltage when it’s in the defrost mode.
If you have a defrost timer you can test it. It can be located under the fridge behind the kick panel on the front. Some are in the fridge with the controls at the top. You can turn the defrost timer till it clicks and everything shuts down. The heater should now come on. If it does, replace the timer because that means the timer is not running. If it doesn't, check the heater and defrost thermostat. Turn the timer again till everything starts back up to end the defrost cycle.
If you have an adaptive defrost control instead of a timer, replace it if the heater and thermostat test good. It is located in the fridge with the controls in some models and on the back in others.

A couple of things can be the source of your problem.

1. The cabinet drain from the evaporator coils can be clogged or iced over. The 60 deg F thermostat is well above this drain and can cycle the defrost timer even if this drain is obstructed.

2. You could very well have an auto deftosting problem with your unit. I.e it is not defrosting at all and the ice build up you see is a result of that.

a. Possible causes

1) Defrost timer
2) 60 Deg F cycle thermostat
3) Heating element
4) wiring


3. You can have an evaporator fan that is not running at full speed or not running at all.

These are the most common problems but there are rare occasions when something as simple as a badly torn door seal can cause the exact symptom you described.


4. You also did not mention if you had an icemaker or not. A leaking / opverflowing / frozen inlet on the TOP rear of the icemaker can also cause this.

If the evaporator coils behind the back panel of the freezer are icing up because of auto defrost failure that will stop the circulation of cold air and eventually affect the freezer too.
The evaporator coil behind the cover on the back wall inside the freezer will ice up under normal conditions. Every 8 to 10 hours for around 20 minutes the defrost timer (or in most newer models the electronic adaptive defrost control) will turn the defrost heater on to melt the built up ice. There is a defrost thermostat which prevents the heater from overheating the freezer by breaking the heater circuit when the temp reaches close to 32 degrees F. The entire cooling system shuts off during the defrost cycle and starts back when the timer advances through the cycle.

If this ice is not melted it will continue to build up until the air can’t flow over the coil to circulate the cold air through the freezer and into the fridge. The temperature change in the fridge is usually noticed first followed by the freezer.

If the defrost thermostat is bad it can prevent the heater from coming on OR it won’t turn the heater off when it gets too warm. It is clamped to the evaporator coil at the top to sense the temp. If it appears to be misshapen it is bad.
With an ohm meter it should show continuity when cold and none when warm.
You can also bypass the thermostat to see if the heater comes on then. If it does then you know the thermostat is bad and needs replaced.

The defrost heater is located on the evaporator. It is in a tube which is at the bottom and can also go up the sides of the evaporator. On some types you can see a burnt spot if it’s bad. With an ohm meter it should show continuity from end to end when disconnected from the wiring in the freezer. You can also test the wiring for voltage when it’s in the defrost mode.

If you have a defrost timer you can test it. It can be located under the fridge behind the kick panel on the front. Some are in the fridge with the controls at the top. You can turn the defrost timer till it clicks and everything shuts down. The heater should now come on. If it does, replace the timer because that means the timer is not running. If it doesn't, check the heater and defrost thermostat. Turn the timer again till everything starts back up to end the defrost cycle.

If you have an adaptive defrost control instead of a timer, replace it if the heater and thermostat test good. It is located in the fridge with the controls in some models and on the back in others.

Your evaporator coils frost up in normal use and every eight hours or so the entire unit shuts down and the defrost heater comes on to melt the frost. This cycle last about 20 minutes. The melted frost drips into a drain pan and through a drain tube to the drain tray under the freezer/refrigerator where it's evaporated by the condenser fan.


Your drain tube may be stopped up with ice at the upper end because it drains too slow because it's stopped up at the lower end in the evaporator pan under the unit at the floor. It can get dust and mold in it. Once you get the ice out at the top a little pressure with a turkey baster will usually clear it out. Flushing it out with hot water and clorox may help

The evaporator coil behind the cover on the back wall inside the freezer will ice up under normal conditions. Every 8 to 10 hours for around 20 minutes the defrost timer (or in most newer models the electronic adaptive defrost control) will turn the defrost heater on to melt the built up ice. There is a defrost thermostat which prevents the heater from overheating the freezer by breaking the heater circuit when the temp reaches close to 32 degrees F. The entire cooling system shuts off during the defrost cycle and starts back when the timer advances through the cycle.

If this ice is not melted it will continue to build up until the air can’t flow over the coil to circulate the cold air through the freezer and into the fridge. The temperature change in the fridge is usually noticed first followed by the freezer.

If the defrost thermostat is bad it can prevent the heater from coming on OR it won’t turn the heater off when it gets too warm. It is clamped to the evaporator coil at the top to sense the temp. If it appears to be misshapen it is bad.
With an ohm meter it should show continuity when cold and none when warm.
You can also bypass the thermostat to see if the heater comes on then. If it does then you know the thermostat is bad and needs replaced.

The defrost heater is located on the evaporator. It is in a tube which is at the bottom and can also go up the sides of the evaporator. On some types you can see a burnt spot if it’s bad. With an ohm meter it should show continuity from end to end when disconnected from the wiring in the freezer. You can also test the wiring for voltage when it’s in the defrost mode.

If you have a defrost timer you can test it. It can be located under the fridge behind the kick panel on the front. Some are in the fridge with the controls at the top. You can turn the defrost timer till it clicks and everything shuts down. The heater should now come on. If it does, replace the timer because that means the timer is not running. If it doesn't, check the heater and defrost thermostat. Turn the timer again till everything starts back up to end the defrost cycle.

If you have an adaptive defrost control instead of a timer, replace it if the heater and thermostat test good. It is located in the fridge with the controls in some models and on the back in others.

If you need help finding your model number see here> http://www.appliancepartspros.com/modelnumber_locator.aspx

To locate your timer, motherboard, control or adaptive defrost control , enter your model number and search for the part or post back on Fixya.
http://www.searspartsdirect.com/partsdirect/index.action?psid=26129238&sid=PSx20071217x00001a

Check the condenser fan underneath the unit accessable form the back behind the cardboard cover. It should be running when the compressor runs. OR Check the evaporator behind the rear cover inside the freezer. Check for ice build up. . Light frost everywhere(NORMAL) or a partial pattern of ice(LOW ON FREON) or nothing(LOW FREON OR COMPRESSOR PROBLEM).
If the evaporator coils behind the back panel of the freezer are icing up because of auto defrost failure that will stop the circulation of cold air and eventually affect the freezer too.

check defrost timer, defrost heater, defrost thermostat. In most newer models the timer has been replaced by an electronic control board. If the heater and thermostat are ok it’ll be the control

I looked at the BACK at the bottom underneath of my Sears Kenmore frost free upright freezer and what was causing the ice buildup was very simple. At the factory, the assembler looped the little hose too high and when the water went into the hose it could not get out due to being too high in one spot! An ice dam will form, blocking ALL water coming through
and freezing up any more water coming down giving you a HUGE wad of ice that is scary!!! I just removed the screw holding the loop that holds the hose and put a bit of warm water down the little hole on the INSIDE (Behind the grate) to melt the remaining ice in the tube.You need to take out 4 screws and remove the grate to see this. I could not believe that this was the problem! I haven't had any ice build up since.Now don't tear your freezer apart before you try this trying to fix the compressor, thermostat etc. It may be the only thing wrong with it!