ClimateMaster 17B0031N04 Thermistor

The ClimateMaster 17B0031N04 Thermistor is a critical NTC (Negative Temperature Coefficient) sensor designed for precision thermal monitoring in water-source heat pumps and geothermal HVAC systems. Featuring a 48-inch lead length with a black thermistor bead, this OEM component provides the 10K ohm resistance (measured at 77°F) required by CXM and DXM control boards to manage freeze protection (FP1/FP2) and discharge air temperature. In the field, a failing 17B0031N04 sensor often triggers Code 4 (Low Water Coil Temperature) or Code 5 (Low Air Coil Temperature) lockouts, even when refrigerant pressures are within spec. This replacement thermistor ensures accurate resistance-to-temperature signaling, preventing nuisance lock-outs and maintaining energy efficiency across the heating and cooling cycles. High-grade durable construction protects against moisture infiltration and wire rub-out, common failure modes in high-vibration equipment cabinets. For veteran technicians, this 48-inch black thermistor offers the necessary slack for routing through sealed electrical harnesses without the need for field-splicing, maintaining the integrity of the 12-pin connection.

Key Benefits for Contractors

• Direct OEM Compatibility: Specifically engineered for ClimateMaster heat pump control logic, ensuring accurate 10K ohm signal processing.
• Extended 48-Inch Leads: Simplifies replacement in large horizontal or vertical cabinets, reaching from the coaxial heat exchanger to the circuit board.
• Precision Freeze Protection: Accurate NTC sensing prevents evaporator icing and heat exchanger ruptures by providing reliable data to the Unit Performance Sentinel.
• Eliminates Fault Codes: Ideal for resolving fault code 4 and 5 diagnostic issues caused by drifted or Out-of-Calibration (OOC) sensors.

Common Questions

How do I verify if the 17B0031N04 thermistor is defective?
Disconnect the sensor and use a digital multimeter to check resistance. At a standard 77°F (25°C), the reading should be approximately 10,000 ohms. If the resistance deviates significantly from the manufacturer’s temperature-resistance chart, the sensor is likely out of calibration and needs replacement.

Can I use this thermistor on the air coil or the water coil?
Yes, the ClimateMaster 17B0031N04 is frequently utilized for both FP1 (water coil) and FP2 (air coil) protection. Confirm the lead length and connector compatibility with your specific CXM or DXM controller series before installation.

Why is my system locking out on a low-temperature code in mild weather?
This is a classic symptom of a drifted thermistor. If the black thermistor sensor reads a higher resistance than actual conditions dictate, the controller falsely identifies a freeze condition. Replacing the sensor restores true temperature feedback.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.