Hi, i was wondering if someone can shine some light on a problem im having with trane rtu unit.im new to hvac talk.model ycd240b3hajb. the induced motor is running continouasly even when t-stat is off.on a call for heat it goes throu the whole cycle and heat comes on.when it satisfies,or when u turn off heat on t-stat everything cycles off but the induced fan motor continues to run.im thinking its the ignition control board that needs to be replaced but want to confirm before i start replacing parts.could it also be the induced motor thats defective causeing it not to shut down?maybe internal switch is stuck closed in motor. any suggestions? thanks