My freezer has started to frost over. It started about 2 weeks ago and is getting worse. What is the cause for the automatic defroster to stop working.

If you are certain that the evaporator fan is running then your automatic defrost function has stopped working.
There are 3 things that cause it to stop working:
1. The defrost control
Item 801 this link:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5206998&diagram_id=26604625#d26604625
2 The defrost heater
Item 826 above link
3. The thermo disc Item 621 above link.
4. The bi-metal thermostat (closed below 60 deg F)
Item 4 can be tested for continuity at temps below 60 deg F.
Item 2 and 3 can be tested at room temp for continuity.

Item 1 the main board controls the defrost cycle which turns the defrost heater on and off.

Primary suspects would be the defrost heater and thermo disc.
Shop areound for the heater if you find that is bad... the link I posted that heater seems VERY expensive to me. The heater PN: WR50X10042 I note prices in the range of $115.00 - $171.00

This PN defrost heater has a history of repeated failure.

Thanks for choosing FixYa,
Kelly

Hi MDstuff,

 

Stopped cooling.  Check the backl of the freezer to see if the Coils are Frosted completely.  The buzzing sound could be the frost touching the  Fan in the back of the freezer behind the cover. Sounds like your Defrost heater has gone south. 

1. unplug the Freezer, power down.. for safety

2. Clean all the food out of your Freezer,

3. Remove the shelves and Ice maker tray stuff.

4. REmove the panel in the back of your freezer

5. Is the Coil(Evaporator, Radiator)you see  frosted up? 

6. At the bottom of this coil. you should see a metal assembly that stretches accros the bottom of the coil with a wire connection on both ends. This is the Defrost heater.

Remove the heater and look to see if the heaterspring inside the glass tube is broken.  If so, get a new one from Ebay, or www.repairclinic.com.

 

In the mean time while your waiting on a part, Use a hair dryer to get rid of all the frost and put your freezer back topgether.  You sahoul get 2 or 3 weeks of service on your Freezer, before it happens again.

 

some component of the automatic defrost system is defective watch this video :::pay special attention to the part about the defrost thermostat since itthe most likely cause with frost built up in the freezer the defrost t-stat should have continunity (the circuit to it should be closed)
here is the link for the video,copy and paste it into your browser if it doesnt link automatically.....http://youtu.be/TnRKj7_BtNw

Really when the fridge frost very excessively there is less cold.
You have to regularly set up defrost setting if your fridge has automatic defrost.
Or your fridge has manual defrost then defrost it twice a week.
To minimize excessive frost, set the temp control setting to just mid- position.
Good luck.

Hi,
There are a few reasons why the refrigerator part will not cool...here are a couple of tips that will help you to figure out why the refrigerantor is not cooling...

Refrigerator not Cooling or Fridge not Cooling
http://www.fixya.com/support/r3662945-refrigerator_not_cooling_or_fridge_not

How to Defrost Refrigerator Defrost Timer Problem
http://www.fixya.com/support/r3771673-defrost_refrigerator_defrost_timer

heatman101

This can be caused by the drain hole below freezer coil being blocked by ice. You MUST remove all ice in drain under freezer coil. Use turkey baster to squirt hot water into hole and use hairdryer to defrost. Possible defrost thermostat is defective. Unit never goes into defrost, ice forms on coil and in floor of freezer. After defrosting may work OK for a week or two but gradually gets warmer because ice is blocking ports where cool air gets to refrig. May also have water in refrig box. Can also be caused by defective defrost timer.

If freezer is icing up, you might have a defrost problem. Frost free models have a heating element that is controlled by a timer to automatically defrost ice, defrost timer turns on defrost heating element every 12 hours to melt ice in freezer and allow good air flow.
You can test defrost element with an ohm meter(located inside freezer coils-will have two wires going to a plug connection), if OK replace defrost timer (located in various places depending on make and model

Occasional defrosting is needed on these units. 2 weeks isn't that bad considering the environment that it is in (your boat). Every time that you open the door, moist air enters the fridge, and the moisture eventually collects on the freezer plate, and freezes. Putting foods into the freezer that are uncovered also contribute to this a great deal, as do putting in warm / hot foods before giving chance to cool down.

These freezers do not have automatic defrosters. The target environment typically has limited power available. Automatic defrosters would easily double the power requirements.

You can also check the door seals on your fridge as well. If they are not sealing properly, they can also let in humid air which then causes moisture to collect on freezer plate.

your ref. has a defrost problem.you will need to take back panel off inside freezer and take your hair dryer again and defrost the system.then you can check your heater,thermostat which is located at top of coils that were defrosted.sometimes the thermostat will pop and not allow it to go into defrost and you need to check defrost timer.

My husband left the freezer door open a couple of months ago, causing ice to form. The loud rattling noise was the fan hitting the ice. The reason why the temperature started to rise but the noise stopped was because the fan had got stuck in a block of ice and was no longer working. Simple solution - defrost the freezer for 24 hours. Touch wood, it is all working fine now!