Sub-Zero 650 model shows error code 21 (Defroster Overheat) EC
Sub-Zero 650 shows error code 21 (Defroster Overheat)EC 21 has been showing for about 6 months. If I open the circuit breaker the EC clears, but returns later. I have cleaned the heat exchangers. The refrigerator runs just fine. What’s the problem and what can I do to fix it?
Expert: Dennis replied:
Sub-Zero Error code: EC21EC24 Cause of error code: Defrost Functionality Issue Solution 1: If temperatures are high call for service. Solution 2: If temperatures are near normal range: a – Clean the condenser b – Press and hold the door ajar alarm key for 15 seconds to clear the error code c – If EC Service light appears, or temperatures rise contact service for repair: 800-440-8583
Defrost overheats means the defrost temperature exceeded the temperature where the heater should have stopped already. This is a problem with the defrost termination thermostat. This part should have open up the heater circuit already once the temperature of the evaporator is above freezing temperature.
My refrigerator is not getting cold but my freezer works fine. I turned all the knobs to the coldest and it’s still not getting cold. Is there anything i can do at home without calling someone to come fix and charge me a lot? Jessie W. Santa Monica, CA
#1: Check the back wall or floor of the freezer section for frost. Check the freezer( evaporator) fan to see if it is running. Check the condenser coils( under the unit ) for blockage from dust. Check the condenser fan (under the unit) to see if it is running.
If you have frost in the freezer there is a problem with the defrost system and the freezer will start to warm eventually as well as the fresh food section. If that is the problem you can check the defrost terminator, defrost heater/s, and the defrost timer or adaptive defrost control If used on your unit or the main control board if so equipped. These things usually require dismantling the freezer and other areas of the refrigerator to be checked.
You could defrost the freezer by disconnecting the power to the refrigerator and letting it sit for at least 24 hours with BOTH DOORS WIDE OPEN to allow the frost to melt completely but it will build up again in 1-2 weeks and start the warming up again.
#2: There is a flap from the Freezer to the Fridge. If it get stuck closed it will not let cold air into the fridge. Take everything out of the freezer to check the flap and see if it is frozen closed with ice or just shut. Once found , flip it open and shut to knock the ice off then leave it open. Being iced up will keep it from being operable. The temperature setting works this flap and it should be open somewhat to let cold air into the fridge. Being you turned the temp gauge to coldest give it 8 hours and check it to see if it is getting cold.
You have a question? Ask appliance repair specialist: (800) 440-8583
Important:1989-2022 ACME SUB ZERO REPAIR SERVICE CO. CA State Licensed, Insured and Bonded, EPA Certified, Sub-Zero® and Wolf® is registered Trade marks of Sub-Zero, Inc. and Wolf Appliance, Inc. All images are copyrighted to their respective owners.