Thermistor - HEX, O-Ring - Kit (W/ Thermister, Clip And O-Ring)

RTG20319DE Thermistor Kit – Temperature Sensor Assembly for Rheem Tankless Gas Water Heaters

The Rheem RTG20319DE is a replacement thermistor assembly designed for monitoring heat exchanger outlet temperature in Rheem tankless gas water heater systems. This kit includes a temperature sensor (thermistor), installation clip, and an O-ring to ensure a proper seal during sensor replacement.

The thermistor plays a critical role in temperature regulation by providing feedback to the control board for real-time burner modulation. This ensures water is heated to setpoint temperatures efficiently and safely, while protecting against overheating or heat exchanger stress.

System Role and Application

• Monitors water temperature exiting the primary heat exchanger
• Sends resistance-based feedback to the system control board for burner adjustment
• Supports precise thermal regulation in both residential and commercial applications

Technical Specifications

• Part Number: RTG20319DE
• Component Type: NTC thermistor with mounting hardware
• Included Components: Sensor (thermistor), O-ring, retainer clip
• System Compatibility: Select Rheem tankless gas models (consult unit-specific service manual for verification)

Installation Notes

Installation requires shutting off water and power to the unit, removing the panel and accessing the thermistor port at the heat exchanger outlet. Sensor insertion must be secure, with O-ring and clip properly seated to maintain a watertight connection. Recalibration is not required, but the system should be tested for accurate temperature response post-installation.

This component should be installed by a licensed technician familiar with electronic temperature sensors and Rheem control logic systems. Improper installation may result in incorrect temperature readings or system fault codes.

Field Considerations

• Inspect wiring harness and connector for corrosion or damage before installing new sensor
• Use dielectric grease where specified to protect contacts
• Ensure replacement part matches OEM resistance rating (as defined in service documentation)

Performance and Maintenance

• Accurate heat exchange monitoring ensures reliable burner control and user comfort
• High-quality materials provide long service life under elevated temperatures and humidity
• Included O-ring maintains seal integrity to prevent moisture intrusion at the probe interface