Samsung Air Conditioner Error Code E422

E422 indicates an open or short circuit fault on the Sump Temperature Fixed 2 sensor in the outdoor unit. The error is triggered when the outdoor temperature is above -10 degrees Celsius and the sensor voltage reads above 4.95V (open circuit) or below 0.5V (short circuit). These voltage thresholds correspond to temperature readings of approximately -30 degrees Celsius and 151 degrees Celsius, which the controller recognizes as physically implausible. The system halts normal operation to protect the compressor until the fault is resolved.

Resetting the unit by cycling power may temporarily clear the error display, but the fault will return quickly if the underlying sensor problem has not been fixed. The control board continuously monitors the sensor voltage during operation and will re-trigger E422 as soon as it detects an out-of-range reading. A permanent fix requires repairing or replacing the faulty sensor or wiring.

If the issue is simply a loose connector, there may be no parts cost, though you will likely still pay a diagnostic service fee in the range of $75 to $150. Replacing the sump temperature sensor typically costs between $20 and $80 for the part, plus labor. If the wiring harness is damaged or the control board needs replacement, total repair costs can range from $150 to $400 or more depending on the unit and local labor rates.

A homeowner with basic electrical knowledge can safely inspect the outdoor unit sensor connector for visible damage, corrosion, or loose connections with the power turned off. However, measuring sensor resistance and replacing components requires a multimeter and familiarity with refrigerant system components. If the wiring and connector look intact, it is best to have a qualified technician perform the resistance measurement and sensor replacement.

It is not recommended to continue operating the system with E422 active. The sump temperature sensor provides data that helps protect the compressor from damage during certain operating conditions. Running the unit without valid sensor input can lead to compressor overheating or other failures that are significantly more costly to repair than the sensor itself.