Samsung oven C-21 code: oven too hot
- Urgency
- High
- Who can fix it
- Moderate DIY
- Time
- About 1 hr
- Repair cost
- $150–$450
The oven temperature sensor is reading higher than the set temperature, so the oven shuts off heating to protect itself. Often the oven is simply too hot, but a faulty sensor or a stuck relay can also cause it.
Likely causes
Listed from most to least common.
- Oven overheated, for example after broiling or a long high-heat cook
- Blocked oven vent so heat cannot escape
- Faulty oven temperature sensor reading too high
- Heating relay on the control board stuck on
- Cooling fan not running
How to fix the C-21 code
Unplug the oven or switch it off at the breaker before removing any panel or filter.
Step 1: Turn the oven off and let it cool
Turn the oven off and leave it to cool completely, which can take an hour. Do not cover the oven or block its vents while it cools.
Step 2: Clear the vent
Make sure nothing such as a baking sheet, foil or a pan handle is covering the oven vent on the back of the cooktop or below the control panel.
Step 3: Reset the power
Once cool, switch off the circuit breaker for the range for at least 30 seconds, then turn it back on and set the oven again.
Step 4: Watch for overheating
If the oven gets much hotter than set, or keeps heating after you turn it off, switch off the breaker and do not use it until it is checked.
Parts that may need replacing
Check your model number on the label inside the door or on the back before ordering.
- Samsung oven temperature sensorCheck prices
When to call a technician
Call a technician if C-21 comes back after the oven has fully cooled and been reset, or if the oven keeps heating when it is turned off. That points to a faulty sensor or control board relay.
A typical repair for this code costs $150–$450 in the US, including parts and labor. Prices vary by area and model.
Models this applies to
- Electric, gas and induction ranges (NE, NX and NSI series)
- Flex Duo ranges with oven divider
- Slide-in and freestanding ranges
- Single and double wall ovens (NV series)
Codes can differ slightly between models. Your owner's manual is the final word and is available from Samsung support.
Common questions
›Is the C-21 code on a Samsung oven dangerous?
It is a safety warning that the oven is hotter than it should be. Turn it off and let it cool. If it keeps happening, stop using the oven until it is repaired.
›Why does C-21 show up after broiling?
Broiling or self-cleaning can push the oven temperature high. If the code clears after cooling and does not return, no repair is needed.