Bard 8402-047 Limit Switch

The Bard 8402-047 Limit Switch is a critical safety component designed for precise thermal regulation within Bard wall-mount HVAC units and furnaces. This 110-180F auto reset limit switch functions as a primary high-limit safety, monitoring discharge air temperatures to prevent heat exchanger damage or hazardous overheating conditions. Engineered for rapid response, the SPST (Single Pole Single Throw) internal contacts are calibrated to open at 180°F and automatically reset once the temperature drops to 110°F. When troubleshooting a Bard HVAC limit switch trip, verify that the static pressure and blower motor RPMs are within spec, as this Bard furnace high limit switch is often the first indicator of restricted airflow or a fouled evaporator coil. This OEM Bard replacement part ensures your equipment maintains factory-spec safety protocols and circuit continuity during high-demand heating cycles. Professional contractors should verify the L180-70 temperature rating printed on the switch flange to ensure technical compatibility with specific model series.

Key Technical Benefits

• Automatic Reset Functionality: Eliminates the need for manual intervention by restoring the circuit once temperatures normalize to 110°F.
• Precise Thermal Calibration: Fixed 180°F cutout protects the heat exchanger from structural fatigue during restricted airflow events.
• OEM Compatibility: Precision-fit flange design ensures a direct drop-in replacement for Bard 8402-047 across various wall-mount configurations.
• Industrial Build Quality: Constructed with high-grade bimetal sensing elements for consistent cycling and long-term reliability in commercial environments.

Common Questions

What causes a Bard 8402-047 to trip frequently?
Repeated tripping is usually caused by restricted airflow, such as dirty filters, blocked returns, or a failing indoor blower motor. If the switch remains open after cooling, the internal bimetal disc may be fatigued and requires replacement.

Can I bypass this switch for testing?
Temporary bypassing is strictly for diagnostic continuity testing. Operating a unit without a functional high limit safety switch can lead to catastrophic component failure or fire hazards.

Is this switch compatible with non-Bard equipment?
While the 110-180F range is standard, the mounting flange and terminal orientation are specific to Bard layouts. Always verify the part number against the unit's wiring diagram.

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.