Home › Air Conditioners › Samsung › E221 / E231 / E251

Samsung Air Conditioner E221 / E231 / E251 Error Code

Outdoor temperature sensor fault. Here is what it means and how to clear it, easiest fix first.

E221 / E231 / E251
May need a pro

One of the outdoor unit's temperature sensors is open, shorted or giving a reading the board can't use. E221 is the outdoor air sensor, E231 the condenser coil sensor and E251 the compressor discharge sensor.

Shown with an E or C prefix depending on model year. Some Samsung commercial (DVM) systems use E237 for the condenser sensor instead of E231. Meanings here come from Samsung service and installation manuals for specific model families; codes vary by series and region, so check your owner's or service manual.

Safety first: unplug the air conditioner (or switch off its breaker) before touching filters, hoses or panels. If you smell burning or gas, or see water near the outlet, stop and call a professional.

How to fix Samsung E221 / E231 / E251

  1. Reset the power at the breaker

    Switch off the breaker that feeds the air conditioner (some systems have separate breakers for the indoor and outdoor units, so switch off both). Wait about five minutes, switch the power back on and restart the unit to see if the code clears.

  2. Note the full code and model number

    If the code returns, write down exactly what the display shows and the model number from the label on the side of the indoor unit. Sensor and board parts differ between models, so this lets the technician bring the right part on the first visit.

When to call a technician

Outdoor sensors sit behind the outdoor unit's panels, so testing and replacement are technician jobs.

Parts that commonly cause E221 / E231 / E251

Order parts by your exact model number so they fit.

Other Samsung air conditioner codes

Frequently asked questions

What does E221 / E231 / E251 mean on a Samsung air conditioner?

One of the outdoor unit's temperature sensors is open, shorted or giving a reading the board can't use. E221 is the outdoor air sensor, E231 the condenser coil sensor and E251 the compressor discharge sensor.

Can I fix Samsung E221 / E231 / E251 myself?

Only the basic checks. You can safely try the steps above, but E221 / E231 / E251 usually points to a part or fault that needs a technician.

What if E221 / E231 / E251 keeps coming back?

A code that returns after a reset and the checks above usually means a part is wearing out. Note when E221 / E231 / E251 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.

Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.

References