Aaon P85390 Limit Switch

The Aaon P85390 Limit Switch is a critical safety component engineered for precision temperature monitoring in high-performance HVAC systems. This L140-20F limit switch serves as a reliable thermal safeguard, designed to automatically break the electrical circuit when internal temperatures reach the 140°F setpoint and reset once they drop by 20°F. As a genuine Aaon replacement part, it ensures seamless integration and maintains the structural integrity of your rooftop unit or furnace. HVAC technicians rely on this fixed-point temperature switch for its consistent calibration and rapid response times, which are essential for preventing equipment overheating and potential system failure. Incorporating this OEM HVAC safety switch into your regular maintenance routine ensures your equipment operates within manufacturer-specified thermal parameters. Its durable construction is built to withstand the rigorous demands of industrial and commercial heating environments, providing long-term reliability and system protection without the need for frequent manual intervention.

• Precise Thermal Protection: Engineered with a fixed 140°F trip point to prevent hazardous overheating conditions.
• Automatic Reset Functionality: Features a 20°F differential, allowing the system to resume safe operation automatically once cooled.
• OEM Compatibility: Specifically designed as a direct-fit component for Aaon HVAC units, ensuring easy installation.
• Enhanced System Safety: Protects vital internal components from heat damage, extending the overall lifecycle of the heating system.

How do I know if my Aaon limit switch needs replacement?
If your HVAC system is short-cycling or the blower fan runs continuously while the heat fails to engage, the Aaon P85390 may have tripped or failed continuity tests.

Is the P85390 switch a manual or automatic reset?
This specific model is an automatic reset limit switch, meaning it will close the circuit again once the temperature reaches the designated reset point.

Where is this limit switch typically located in an Aaon unit?
It is usually mounted near the heat exchanger or within the burner assembly area to accurately monitor the highest ambient temperatures within the cabinet.

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.