Bard HVAC 8402-020BX Limit Control

For veteran technicians and contractors maintaining Bard HVAC wall-mount systems, the Bard HVAC 8402-020BX Limit Control is the essential safety component for precise temperature regulation. This primary limit control features a factory-calibrated 135-120 temperature range, meaning it is engineered to open the circuit at a 135°F high-limit rise and automatically reset once the temperature drops back to 120°F. Whether you are performing a furnace repair or routine HVAC system diagnostics, using the 8402-020BX ensures total compatibility, as this part is identical to 8402-020 but comes in professional individual packaging for field readiness.

Built with durable construction for both industrial and residential use, this limit switch protects the heat exchanger and blower motor from overheating conditions. Its normally closed (NC) design is a critical fail-safe in air handler repair and heating system maintenance, providing reliable performance in high-demand environments. If you are seeing furnace error codes related to an open limit, this OEM Bard replacement part is the standard solution for restoring safe equipment operation.

Key Benefits:

• Direct OEM Compatibility: Specifically designed for Bard HVAC units, replacing both 8402-020 and 8402-020BX with no mounting modifications required.
• Precision Calibration: Features a fixed 135°F trip point and a 120°F reset to prevent short-cycling and ensure equipment safety.
• Rugged Reliability: Engineered for long-lasting performance in commercial HVAC systems and residential wall-mount applications.
• Field-Ready Packaging: The "BX" suffix indicates individual factory packaging, protecting the sensitive internal contacts during transit to the job site.

Common Questions:

Is the 8402-020BX a direct replacement for the 8402-020?
Yes, these parts are technically identical. The BX suffix simply denotes that the part is individually boxed by the manufacturer, rather than being part of a bulk master pack.

What causes this limit control to trip frequently?
In Bard wall-mount applications, frequent tripping is often caused by restricted airflow, such as a dirty air filter, a failing blower motor, or blocked supply registers. Always verify static pressure when replacing a limit switch.

Can I test this switch with a multimeter?
Technicians can verify the 8402-020BX by checking for continuity (0.0 ohms) across the terminals when the switch is below 135°F. If the switch measures 0.L (open) at room temperature, it has failed and requires replacement.

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.