Williams P322391 Thermocouple

The Williams P322391 Thermocouple is a high-output OEM replacement part designed for precision flame sensing in Williams wall furnaces. This specialized thermocouple with junction box serves as the direct updated version for P321828, providing a seamless retrofit for older pilot assemblies. As a veteran-grade furnace safety component, it features an integrated vent limit switch and a robust terminal block transition, ensuring the millivolt signal is accurately transmitted to the gas valve while monitoring for dangerous flue conditions. Engineered for durability in high-cycle environments, the P322391 maintains critical pilot flame sensing to prevent unburned gas buildup, making it an essential stock item for professional HVAC service calls involving Williams comfort products.

• Direct OEM Match: Drops into standard Williams pilot assemblies without the need for mounting bracket modifications.
• Enhanced Safety Logic: Includes a factory-wired vent limit switch to offer secondary protection against downdrafts and venting failures.
• Junction Box Integration: Simplifies field wiring with a secure junction block for reliable electrical connections in high-temperature zones.
• Broad Compatibility: Verified for use with a wide range of models, including 3508731, 4007731, 5008732, and 6508732 series.
• Reliable Millivolt Output: Maintains consistent voltage to keep the standing pilot engaged and prevent nuisance system lockouts.

Is the P322391 compatible with older P321828 installations?
Yes, the P322391 is the official manufacturer-designated replacement for P321828. It maintains the same physical footprint while offering improved lead protection and connection stability.

Why does this thermocouple include a junction block?
The junction box and terminal block design are specific to Williams wall furnaces that utilize a safety circuit loop. This allows the vent limit switch to be wired in series with the thermocouple signal, providing a physical break in the circuit if the vent overheats.

What is the typical length of this thermocouple?
This Williams furnace part typically features a 24-inch lead, suitable for standard wall-mounted gravity and counterflow furnace configurations.

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.