Lochinvar & A.O. Smith 100074316 Thermistor

When you are dealing with a lockout on a high-efficiency Lochinvar Knight or A.O. Smith commercial water heater, the 100074316 Thermistor is often the culprit behind exhaust-related error codes. This genuine DV exhaust thermistor assembly is a critical NTC (Negative Temperature Coefficient) sensor designed to monitor flue gas temperatures. It provides real-time resistance feedback to the control board, ensuring the system stays within safe thermal parameters and preventing damage to PVC or CPVC venting components. As a direct OEM replacement part, it eliminates the calibration drift common with aftermarket sensors, ensuring your exhaust gas temperature monitoring remains accurate for optimal combustion cycles.

The 100074316 is engineered for a precise fit in the exhaust manifold, utilizing a high-grade sensing probe that resists the corrosive effects of flue condensates. Whether you are servicing a Lochinvar boiler or a commercial tankless unit, this assembly is vital for preventing nuisance trips and high-limit shutdowns. Replacing a fouled or failing thermistor restores the communication link between the venting system and the integrated control module, maintaining the high-efficiency performance your customers expect from professional-grade HVAC systems.

• Optimized Safety: Accurately tracks exhaust temperatures to prevent overheating and potential vent system failure.
• OEM Precision: Guaranteed compatibility with Lochinvar and A.O. Smith equipment, ensuring correct resistance-to-temperature mapping.
• Direct Replacement: Designed for an exact fit, reducing labor time during service calls.
• Corrosion Resistance: Built to withstand the harsh environment of high-efficiency condensing flue gases.

• What are the symptoms of a failing exhaust thermistor? You’ll typically see specific error codes related to "Exhaust Overheat" or "Sensor Open/Short," even if the actual temperatures seem normal.
• Can I test this part with a multimeter? Yes, as an NTC sensor, you should see resistance values change predictably as the probe is exposed to varying heat levels.
• Is this assembly compatible with both Lochinvar and A.O. Smith? Correct. This part number is standardized across several major brands under the manufacturer's umbrella for condensing water heaters and boilers.

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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.