What is defrost overheat? - Sub-Zero 650/SRH Stainless Steel

The Delafield 6000xl tripping the main breaker and displaying "DEF" on the screen could indicate a problem with the refrigeration system's defrost cycle. The defrost cycle is necessary to melt any built-up ice or frost on the evaporator coils and maintain efficient cooling. If the defrost cycle is not functioning properly, it could cause the unit to overheat and trip the main breaker. To troubleshoot this issue, you can try the following steps: Check the defrost timer: The defrost timer controls the duration and frequency of the defrost cycle. If the timer is not functioning properly, it could cause the defrost cycle to run too long and cause the unit to overheat. Check the defrost thermostat: The defrost thermostat monitors the temperature of the evaporator coils during the defrost cycle. If the thermostat is not functioning properly, it could cause the defrost cycle to run too long and cause the unit to overheat. Check the defrost heater: The defrost heater melts the ice and frost on the evaporator coils during the defrost cycle. If the heater is not functioning properly, it could cause the defrost cycle to run too long and cause the unit to overheat. If you are unable to diagnose and resolve the issue, it is recommended to seek the assistance of a professional refrigeration technician. They will be able to diagnose and repair the problem to restore proper operation of the Delafield 6000xl refrigeration system.

this subzero had the same error code. when i tested defrost components find out that defrost thermostat is bad, so i replaced it, and it does work just fine now.

possible erratic or defective defrost terminator.

Is it the defrost heater element? There are several possibilities. Check defrost timer operation and output, check overheat limit klixon (attached to evaporator), check heater continuity.

Defrost is turning the fans on so there is probably an issue with the fan controls on the car.

Turn ur car on defrost and check to c if fan is running. It should kick on on defrost. If it does not try checking fan or relay or your fuse. If of does and still gets hot maybe a good coolant flush will work.

To troubleshoot this types of problem,click the link below :----http://howtobyme.blogspot.in/2012/02/heater-blows-only-from-defrost.html
--------Go through the procedure to confirm the issue.

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Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

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Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

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This will help.Thanks.

Most likely you have lost your refrigerant in a leak, since the compressor is running but not cooling.

You need to unplug and get serviced or your compressor will overheat and fail which will be much more expensive.

EC 21 has nothing to do with the refigerator. From the 600-2 series service manual page 3-21 EC 21 is Defrost Overheat fault.
The defrost system is only in the freezer and on a completely seperate refrigeration system. Clear the EC by holding the bell key pad down until you here a tone this is going to be a minimum of 15 but can be as long as 30 depending on the generation of your appliance. The part that you will most likely need to replace is the defrost terminator which stops the defrost cycle. You may have also had a problem in the refrigeration section which did fix by yourself, good job.

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