the Armstrong 811 offers exceptional resistance to wear and water hammer

For systems exceeding 2 PSI

allowing the HVAC high limit switch to re-engage once the system cools to 110°F

This component is the direct replacement for S1-024-21671-002

Common Questions: What is the rotation direction for this blade

Utica-Dunkirk 240009793 Pressure Switch 320720-756 the Armstrong 811 offers exceptionalThe Utica Dunkirk 240009793 Pressure Switch is a critical OEM furnace replacement part designed for specific ECR International heating systems, including Dunkirk, Pennco, and Utica Boiler models. This 0. 50" WC pressure switch acts as a primary safety mechanism, monitoring the draft inducer motor to verify adequate negative pressure and airflow before allowing the ignition sequence to proceed. As a veteran grade HVAC safety control, it replaces worn