The thermistor sensor tells the AC the room and evaporator temperatures. When it fails, cooling becomes erratic, the AC may not stop at the set temperature, or shuts down randomly.
See if any of these signs match your device — each one increases the likelihood of this fault.
These are the causes we encounter while repairing AC temperature sensor failure — ranked from most to least common.
Room thermistor failed
Evaporator coil thermistor failed
Sensor wire broken internally
PCB can't read the sensor signal
Humidity damage to the sensor
Any of the following = a danger signal — call now and don't try to fix it yourself.
On-site diagnosis, clear pricing before any work, and a documented 6-month warranty.