Blocked Vent Switch L300F | NBK-21056

NBK-21056 – Blocked Vent Switch L300F  The NBK-21056 Blocked Vent Switch L300F provides critical safety protection for furnaces, greenhouse heaters, and HVAC systems. Designed to detect blocked vent conditions, it automatically interrupts power when exhaust temperatures exceed 300°F (L300F). This safeguard prevents overheating and ensures your equipment operates safely and efficiently under all conditions. Key Features: • Critical Safety Component: Opens at 300°F to protect against blocked or restricted venting • High-Temperature Operation: Ideal for systems exposed to elevated exhaust temperatures • OEM-Equivalent Fit: Matches the specifications of original blocked vent switches for direct replacement • Durable Construction: Engineered to withstand continuous high-heat environments for long-term reliability Specifications: • SKU: 21056 • Category: Miscellaneous / Blocked Vent Switch • Description: NBK-21056 Blocked Vent Switch L300F • Trip Temperature: Opens at 300°F • Equivalent To:    – Modine 4034100    – Modine 5H0730570005    – Modine 5H73057 Why Choose This Replacement: Replace worn or malfunctioning blocked vent switches to ensure your heating system operates safely. This switch automatically shuts down your system if unsafe exhaust or venting conditions occur, protecting both your equipment and environment. Shipping & Availability: This item is a special order product from NBK and typically requires 1–2 additional business days for processing prior to shipping.