What C-20 / C-21 / C-22 Means
C-20, C-21 and C-22 are the temperature sensor errors on Samsung’s US microwave article, covering the thermistor that tracks cavity or part temperature rather than the food-sensing group.
Common Causes of C-20 / C-21 / C-22
- Temperature sensor open or shorted
- Sensor wiring or connector damaged
- Sensor reading affected by moisture reaching the circuit
🔧 One Safe Check You Can Try
Power the microwave off for about 60 seconds, let any moisture on the control panel dry, then restart and run a short heat cycle. If C-20, C-21 or C-22 returns, the temperature sensor or its wiring is the next thing a technician checks.
⚠ Why You Shouldn't Go Further Than That
- The temperature sensor sits inside the cavity housing next to the magnetron circuit, which holds a charge even unplugged and is only opened by a technician.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.