Samsung Samsung NX60A6511SS 6.0 cu. ft. Smart Freestanding Gas Range C-21 Error Fix: Self-Clean Over-Temperature

Error code C-21 on the Samsung Samsung NX60A6511SS 6.0 cu. ft. Smart Freestanding Gas Range means: Self-Clean Over-Temperature. The oven exceeded the maximum safe temperature during a self-clean cycle. The self-clean cycle heats the oven to approximately 900°F to burn off residue. If the temperature exceeds the safety limit, C-21 appears and the cycle aborts. The door remains locked until the oven cools below a safe threshold. Allow the oven to cool completely. If C-21 appears repeatedly, the temperature sensor or control board may not be regulating self-clean temperature correctly.

The most successful fix is "Test and Replace Oven Temperature Sensor or Control Board" (hard difficulty, ~90 minutes). Estimated DIY cost: $20-$40. HomeMD has 2 community-ranked fixes for this error.

This error is rated critical severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test and Replace Oven Temperature Sensor or Control Board") is rated hard difficulty and takes about 90 minutes. Tools needed: T20 Torx screwdriver, Multimeter.

DIY cost: $20-$40. Professional repair typically costs $200-$350. Many homeowners save money by trying the top-ranked community fix first.

The Samsung Samsung NX60A6511SS 6.0 cu. ft. Smart Freestanding Gas Range has 8 other known error codes, including: C-10 (Cooktop Burner Anomaly), C-24 (Convection Fan Timeout), C-d0 (Main Board Communication Error), C-d1 (Sub-Board Communication Error), C-dC (Display Communication Error), and 3 more.

Error code C-21 also appears on 1 other Samsung model: Samsung NE63A6511SS 6.3 cu. ft. Smart Freestanding Electric Range. The fix may vary by model, so check each model's specific page for tailored repair steps.