I found the thermistor and it test open with an ohm meter. Does it need to be warmed up to test. Number on the thermistor is AP3963045.
The thermistor on the unit should be read for resistance using a ohm meter. The resistance should be between 48k and 52k ohms of resistance at 77 degrees Fahrenheit. At 140 degrees the resistance would be 12K to 13 k ohms of resistance. If outside this range then the thermistor would need to be replaced.