The Toyotomi High Limit Thermistor, part number 20476974, is a genuine replacement safety sensor used in select Toyotomi and Oil Miser heater models to monitor internal temperature and help prevent overheating. It detects when the heat exchanger or combustion chamber area exceeds specified temperature thresholds and signals the control system to reduce burner output or shut down the heater for safety. This thermistor is manufactured to original equipment specifications to ensure proper fit and reliable temperature sensing in the compatible appliances.
This replacement thermistor is used during maintenance or repair when the original sensor is faulty, exhibits inconsistent temperature readings, or has failed due to wear, heat exposure, or age. Proper installation follows the model-specific parts diagram and service instructions so the sensor is correctly routed and connected to the heater’s control system. Verifying secure electrical connections and correct placement helps maintain accurate temperature monitoring and safe heater operation.
What’s Included: One (1) Toyotomi high limit thermistor for the specified heater model.
Installation Limits: For use only on compatible Toyotomi and Oil Miser heaters; install with power disconnected and follow manufacturer service procedures to ensure correct routing and secure electrical connection.
Compatibility: Fits Oil Miser 128HH, High Limit Thermistor is located next to Heat Exchanger Assembly.
