Bard HVAC 8402-105 Limit Control

The Bard HVAC 8402-105 Limit Control is a critical safety component designed for high-limit temperature monitoring in Bard wall-mount units and forced-air systems. This L230-30 limit switch features a 7-inch insertion length, providing deep-reach sensing into the heat exchanger plenum to ensure accurate thermal response. It is engineered to open the electrical circuit at 230 degrees Fahrenheit and automatically reset when the temperature drops by 30 degrees, preventing heat exchanger damage and hazardous operating conditions. As a genuine OEM replacement for the obsolete 8402-089BX, this part maintains the factory-specified safety parameters required for commercial and industrial HVAC applications. The inductive load rating and single-pole single-throw (SPST) configuration provide reliable switching under standard 24V or 120V control circuits. For contractors performing HVAC preventative maintenance, installing this direct-fit Bard 8402-105 ensures your equipment remains compliant with manufacturer safety standards without the need for field modifications.

• Direct OEM Replacement: Replaces the 8402-089BX model, ensuring perfect mechanical and electrical compatibility.
• Extended 7-Inch Probe: Optimized for large-cabinet Bard units to detect stagnant air or overheating deep within the assembly.
• High-Limit Precision: Calibrated for a 230-degree cutout to protect the integrity of the heat exchanger and surrounding components.
• Automatic Reset: Features a fixed 30-degree differential, allowing the system to resume normal operation once safe temperatures are restored.
• Heavy-Duty Construction: Designed to withstand the high-cycle demands of commercial heating systems and telecom cooling units.

What causes a Bard limit control to trip frequently?
Frequent tripping is usually a symptom of restricted airflow. Check for a clogged air filter, a failing blower motor, or obstructed return air grilles. If the airflow is verified as adequate, the internal bi-metal disc in the 8402-105 may have weakened from age, requiring a replacement.

Is the 8402-105 compatible with older 8402-089BX switches?
Yes, the 8402-105 is the current manufacturer-authorized replacement for the 8402-089BX. It matches the original L230-30 specifications and 7-inch probe depth exactly.

Can I use a limit switch with a different probe length?
It is not recommended. Using a shorter probe may cause a delay in temperature sensing, while a longer probe may physically interfere with heat exchanger fins. Always match the 7-inch specification for these specific Bard applications.

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.