Midea Air Conditioner Error Code Er

The Er code on a Midea air conditioner indicates a room temperature sensor open circuit or short circuit failure. The indoor ambient temperature thermistor is sending a signal that the control board cannot recognize as a valid temperature reading. The unit will not operate normally until the fault is diagnosed and corrected.

The unit will typically stop normal operation when the Er code appears, which is a protective response to prevent incorrect temperature control. Attempting to force the unit to run without a functioning room temperature sensor can result in improper cooling cycles or compressor behavior. It is best to resolve the fault before resuming regular use.

Powering the unit off and back on may temporarily clear the display, but the Er code will return if the underlying sensor or wiring fault has not been corrected. A reset does not repair a failed thermistor or broken wire. The fault must be physically diagnosed and repaired for the error to stay cleared.

A knowledgeable DIYer can start by checking that the sensor connector is firmly seated and that the wiring has no visible damage. Testing the thermistor with a multimeter in resistance mode will confirm whether the sensor itself has failed. If the sensor reads open or shorted, replacing it is a relatively straightforward repair, though working inside the unit requires disconnecting power first.

If only the room temperature thermistor needs replacement, parts typically range from a few dollars to around $20 to $40 depending on the model. If a technician performs the repair, total costs including labor will generally range from $75 to $200. Control board replacement, if required, is more expensive and could bring the total to $150 to $400 or more.