Bard 8402-031 Limit Switch

The Bard 8402-031 Limit Switch is a critical safety component designed for high-limit temperature regulation in Bard HVAC systems and wall-mount units. Engineered for precise thermal monitoring, this OEM replacement limit switch features a fixed set point that shuts down the heating circuit when internal temperatures reach 155°F (Open), preventing heat exchanger damage and system overheating. Once the unit cools to 130°F (Closed), the switch resets the circuit to resume normal operation. This 155-130 limit control is built with a robust bimetal disc for rapid response times and reliable switching cycles in demanding commercial and residential environments. As a veteran-grade HVAC safety switch, it ensures the equipment operates within manufacturer-specified thermal parameters, protecting the blower motor and heat strips from excessive heat soak caused by restricted airflow or filter bypass issues.

• Precise Thermal Protection: Factory-calibrated 155°F trip point ensures immediate HVAC system protection during overheat conditions.
• Automatic Reset Logic: Closes at 130°F to restore system functionality without manual intervention once safe temperatures are reached.
• OEM Compatibility: Genuine Bard 8402-031 part ensures a perfect fit and maintains HVAC equipment safety standards.
• Durable Construction: High-grade materials designed to withstand the high-cycle demands of furnace limit control applications.

What causes a Bard 8402-031 limit switch to trip?
Typically, a tripped limit switch is caused by restricted airflow. This often stems from a dirty furnace air filter, a failing blower motor, or blocked return air grilles that cause heat to build up beyond the 155°F threshold.

Can I bypass this switch for testing purposes?
While technicians may briefly jump a switch for diagnostic continuity tests, you should never bypass a high limit switch during permanent operation as it removes a primary safety barrier against fire and heat exchanger cracking.

How do I know if my Bard limit switch is faulty?
If the HVAC blower runs constantly while the burners or heat strips won't engage, or if the switch shows no continuity at room temperature, the internal bimetal disc may be stuck open, requiring a Bard replacement part.

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.