Weil McLain 511-624-403 Pressure Switch

The Weil McLain 511-624-403 Pressure Switch is a critical OEM safety component specifically calibrated for CGi-5 Series gas boilers and select CGs-5 models. Operating with a precise fixed set point of 1.22" W.C., this air pressure differential switch ensures that the inducer fan is generating sufficient draft before allowing the ignition sequence to proceed. It is designed for standard altitude installations ranging from 0 to 1,999 feet. This genuine Weil McLain part is a direct replacement for part number 511624403, engineered to handle both natural gas and propane (LP) combustion environments. For field technicians troubleshooting internal boiler air flow issues or "air flow not proven" fault codes, verifying the differential pressure with a manometer is recommended before replacing the high-limit safety switch. This SPST switch features a durable housing designed to withstand the thermal cycling and vibration common in hydronic heating cabinets, ensuring long-term reliability in commercial and residential boiler maintenance applications.

• Precise 1.22" W.C. Calibration: Perfectly matched to Weil McLain CGi-5 boiler combustion requirements to prevent short-cycling and safety lockouts.
• OEM Compatibility: Guaranteed fit for Weil McLain 511-624-403, eliminating the mounting and electrical issues associated with universal aftermarket switches.
• Dual Fuel Versatility: Fully rated for both natural gas and propane gas configurations.
• Standard Altitude Optimized: Specifically engineered for peak performance in installations from sea level up to 2,000 feet.
• Direct Plugin Integration: Features standard spade terminals for a fast, secure electrical connection to the integrated boiler control module.

• What does it mean if my boiler shows an 'Air Flow Not Proven' light? This often indicates that the 511-624-403 pressure switch has not closed, either due to a failing inducer motor, blocked venting, or a ruptured switch diaphragm.
• Can I use this switch at high altitudes (above 2,000 feet)? No, this specific model is calibrated for 0-1,999 feet. High-altitude applications generally require a different set point (e.g., 511-624-520) to compensate for thinner air.
• Does this part include the silicone tubing? This is the switch assembly only. We recommend inspecting your existing silicone pressure switch tubing for cracks or moisture during installation.

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.