Weil McLain 381-800-477 Vent Damper

When you are servicing gas-fired systems, the Weil McLain 381-800-477 7-inch vent damper is the critical OEM component required to maintain proper draft and combustion efficiency. This automatic vent damper is the verified direct replacement for the legacy Weil McLain 510-512-347 model. Engineered specifically for boiler venting systems, this unit facilitates fuel savings by closing the flue during the off-cycle to prevent standby heat loss, while ensuring the mechanical damper opens fully before the burner ignites. It is compatible with a wide range of cast iron units, including the Weil McLain CGa, CG, PFG, and EG Series boilers. Designed for high-temperature durability, this 7" assembly integrates seamlessly with existing boiler controls to prevent carbon monoxide spillage and optimize HVAC efficiency. For seasoned contractors, using this genuine 381-800-477 vent damper ensures a plug-and-play installation that meets original factory specifications for safety and performance.

Key Benefits

• Standby Heat Retention: Eliminates the "chimney effect" by closing the flue when the burner is off, significantly reducing energy waste.
• Direct OEM Compatibility: Specifically designed for Weil McLain GC/CGA/EG series, ensuring correct wiring harness alignment.
• Safety Interlock: Features a proven safety circuit that prevents boiler ignition unless the damper blade is in the fully open position.
• Robust 7-Inch Design: Built to withstand the corrosive environment of flue gases in residential and commercial hydronic heating applications.
• Efficient Replacement: Standardized mounting and electrical connections allow for a rapid swap of the outdated 510-512-347 models.

Common Questions

Which boiler models are compatible with this damper?
This 7-inch assembly is optimized for Weil McLain CGa-7/8, CG-7/8, PFG-5, and various EG series gas-fired boilers. Always verify the vent pipe diameter before ordering.

Is the 381-800-477 a drop-in replacement for the 510-512-347?
Yes, the 381-800-477 is the official manufacturer-designated substitute for the older 510-512-347, maintaining the same form, fit, and electrical function.

What happens if the damper fails to open?
The integrated safety switches will break the 24V circuit to the gas valve, preventing the boiler from firing until the exhaust path is confirmed clear.

This item is not eligible for free shipping.

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.