Samsung Air Conditioner Error Code *1

The *1 error code on a Samsung air conditioner indicates a room thermistor sensor fault on the indoor unit whose address matches the number represented by the asterisk. The thermistor monitors return air temperature and is essential for normal operation. The system generates this code when the signal from the thermistor is missing or outside the expected range. The first thing to check is whether the thermistor is properly connected at the CN8 connector on the indoor unit PCB.

It is not recommended to continue running the unit while the *1 error is active. Without a functioning room thermistor, the system cannot accurately regulate temperature or respond to thermal conditions, which can lead to improper operation and potential equipment damage. The unit will typically lock out or limit operation automatically when this fault is detected.

A power reset may temporarily clear the *1 error code from the display, but the fault will return if the underlying thermistor problem has not been corrected. Because the system continuously monitors the CN8 input, any ongoing connection issue or sensor failure will trigger the code again once the unit attempts to operate. A reset is useful for confirming whether a fault was intermittent, but it is not a substitute for diagnosing and repairing the thermistor circuit.

Start by locating the indoor unit identified by the address in the error code and checking that the room thermistor is firmly connected at the CN8 port on the control board. If the connection is secure, use a multimeter to measure the thermistor's resistance and compare it to the expected value for the current room temperature. A reading that is open, shorted, or far out of range indicates a failed thermistor that needs replacement. If the sensor and wiring both check out, the indoor PCB may need to be evaluated.

If only the thermistor sensor needs replacement, parts typically range from $15 to $60 depending on the specific indoor unit model, with labor costs adding $75 to $200 depending on your region and service provider. If the indoor PCB is at fault, total repair costs including parts and labor can range from $200 to $500 or more. Getting a diagnostic visit from a qualified technician will help narrow down exactly which component is causing the fault before committing to parts costs.