A C-20 error is almost always caused by a failed oven temperature sensor probe or damaged wiring in the sensor circuit. In most service calls, replacing the sensor probe located in the back of the oven cavity resolves the issue immediately.
When your Samsung oven throws a C-20, the control board can't get a usable reading from the temperature sensor and it shuts everything down. Ignore it and the oven stays dead. I've had customers wait two weeks thinking it'll clear on its own. It won't. The sensor is about $40 and swaps out in 20 minutes. The board is almost never the problem, so don't go ordering a $200 board before you've tested the $40 sensor.
Phillips #2 screwdriver, Digital multimeter (auto-ranging works fine)
What Does the C-20 Code Mean?
Nine times out of ten, this is a hardware failure, not some software glitch you can reboot away. The control board reads that sensor resistance constantly, and the second it drops to near zero, every heating element shuts off. I replaced two of these sensors just last Tuesday on Samsung ranges, both right after self-clean cycles. You can try flipping the breaker, sure. But if that sensor is shorted, the code comes right back within seconds of power-up and you'll know exactly what you're dealing with.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Sensor Probe Failure75%
Wiring/Harness Damage15%
Main Control Board Fault10%
Symptoms You May Notice
Oven displays C-20 and won't heat at all, bake and broil both completely dead
The error code appears the moment you try to start any cooking cycle
Code showed up right after a self-clean cycle finished and hasn't cleared since
Oven was working fine, you pushed it back against the wall, and an hour later C-20 appeared
Even after a breaker reset, the code is back on the display within seconds of power-up
Can you reset a Samsung oven to clear the C-20 code?
Flip the oven circuit breaker off and wait a full five minutes. Not one minute. Five. This completely drains the control board memory. Flip it back on and don't touch any buttons for 30 seconds. If the display comes up clean, try starting a bake cycle at 350 to confirm the sensor's reading correctly. If C-20 comes right back within seconds, there's a real electrical fault the board is detecting and you'll need to fix the underlying problem before the reset will hold.
Tools Required for Diagnosis
Phillips #2 screwdriverDigital multimeter (auto-ranging works fine)Cut-resistant work glovesNeedle-nose pliersFlashlight or headlamp1/4-inch nut driver
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
ComponentComponent Under Test
Expected Range1050–1100 ohms
ConditionIf Open (OL) or infinite, replace component.
Frequently Asked Questions
Can I still use my oven if it shows a C-20 error?
Nope. Samsung programs this so none of the heating elements will run when C-20 is active. Bake, broil, convection, all dead. The oven's locked itself out on purpose because it genuinely doesn't know how hot it is in there. It's actually a smart safety feature even if the timing is awful, like right before Thanksgiving. Don't try to work around it. Fix the sensor and you'll have full function back.
Why did the C-20 error appear after a self-cleaning cycle?
Self-clean locks your oven at over 800 degrees for several hours. That's way hotter than anything you'd ever cook at, and the sensor probe sits right there in the middle of that whole situation. I've seen sensors test perfectly fine before a self-clean and fail immediately after. The thermistor element inside just can't take that kind of sustained extreme heat forever. If your oven is more than 5 years old, honestly I'd skip self-clean and just use oven cleaner spray. That service call is going to cost you more than the spray.
Is the C-20 error the same as a C-21 error?
Same sensor, different failure mode. C-20 is a short circuit, meaning the resistance dropped too low, which reads to the board as an impossibly hot oven. C-21 is the other direction, it means the sensor read an actual over-temperature condition or the board saw a resistance that's way too high. If you got a C-21 during the self-clean and then a C-20 after it cooled down, the sensor probably fried during the cycle and fully shorted as it cooled. That's a pretty classic one-two punch. Replace the sensor and you should clear both.
How much does it cost to fix a C-20 error?
DIY with a new sensor is usually $35-60 for the part. Genuine Samsung sensors run about $50, aftermarket ones around $35 and they work fine in my experience. A tech visit is going to be $150-250 all in depending on your area. Honestly this is one of the easier DIY repairs on a Samsung oven. Two screws hold the probe in the oven cavity, you swap the connector, done. Total time maybe 30 minutes including pulling the oven out and back. Good one to tackle yourself.
Do I have to pull the oven out to replace the sensor?
For just swapping the sensor probe itself, sometimes you don't need to. Unscrew the two screws inside the oven cavity holding the probe bracket, then gently pull the probe through. The connector is usually tucked just inside the back wall behind some insulation. Some Samsung models let you reach it from inside if you've got small hands and a flashlight. But usually I pull the oven out anyway to get clean access. Trying to fish that connector through a tiny opening blind is how you drop the wire inside the wall and have a much, much worse day.
What's the part number for the Samsung oven temperature sensor?
Most Samsung ranges from the last 10 years use either DG32-00002B or DG32-00002G depending on the model. Check your model number on the sticker inside the door frame or on the back of the unit and search it on any appliance parts site. The sensor comes up as a top result for most Samsung ranges because it's such a common replacement. Usually ships next day from a parts warehouse and it's not a hard install.
Models Known to Experience C-20 Errors
This repair applies to most Samsung ovens with this error code. Common model numbers include: