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Weil McLain 381-800-445 Damper Assembly

Weil McLain 381-800-445 Damper Assembly

Weil McLain

The Weil McLain 381-800-445 Vent Damper Assembly is the 9-inch diameter automatic vent damper with wiring harness for Weil-McLain gas boilers. Weil-McLain's EG and EGH boiler manual lists the 381-800-445 as the 9-inch damper for the EGH-85, and it is supplied as a complete assembly with the damper motor 510-512-337 and the damper wiring harness 591-391-795. If you are searching for 381-800-445, this is the factory part.

An automatic vent damper closes the flue while the burner is off, which stops warm room air from chasing up the chimney, and opens fully before the burner is allowed to fire. The actuator, a Johnson M35BE-1C also sold as the 510-512-337, drives the blade, and the harness connects the damper to the boiler control. Weil-McLain's manual is blunt about it: only the dampers it lists are approved for these boilers, the blade position indicator must be visible, the harness has to be strain relieved and kept off hot surfaces, and a damper must never be jumpered. Once the boiler has run, unplugging either end of the harness causes a safety lockout until it is reconnected.

Weil-McLain sizes its dampers by flue diameter. The 381-800-445 is the 9-inch size, the 381-800-446 is the 10-inch size for the EGH-95 and EGH-105, and the 381-800-447 is the 12-inch size for the EGH-115 and EGH-125. Do not buy by looks. Measure the flue collar, check the boiler model on the rating plate, and match both to the part number. Our team will confirm the match if you send the boiler model and serial number.

Key Benefits

  • Complete Assembly: The 381-800-445 includes the damper motor 510-512-337 and the wiring harness 591-391-795, so you are not hunting for the actuator and harness separately.
  • Listed For The EGH-85: Weil-McLain's EG and EGH manual lists the 9-inch damper 381-800-445 for the EGH-85, so you are working from the manufacturer's own table.
  • Stops Standby Heat Loss: The damper closes the flue between cycles, which keeps heat in the boiler room and in the house instead of up the chimney.
  • Safety Interlock Built In: The harness ties the damper into the boiler control, and Weil-McLain warns that a vent damper must never be jumpered or bypassed.

Common Questions

  • What is the Weil McLain 381-800-445? It is the 9-inch vent damper assembly with wiring harness. It includes the damper motor 510-512-337 and the harness 591-391-795.
  • Which boiler does the 381-800-445 go on? Weil-McLain's EG and EGH manual lists it as the 9-inch damper for the EGH-85. Check your boiler model on the rating plate and measure the flue collar. Send us the model and serial number and we will confirm before you buy.
  • Can I use a different brand of damper? Weil-McLain states that only the dampers listed in its manual are approved for these boilers. Use the listed part number, and never jumper or bypass a vent damper.

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.