and Ducane models using the 31J9101 specification

Optimal Airflow: Designed for an "Air Toward Motor" configuration to maximize system cooling and heat exchange efficiency

It is designed to fit 3/4" OD ACR tubing or 5/8" nominal K/L/M copper pipe

It means the switch opens (breaks the circuit) when the temperature hits 240°F and automatically resets (closes) after the temperature drops by 40°F

Williams P100100 Door Gasket and Ducane models using theThe Williams Furnace Company P100100 Door Gasket is a critical high temperature seal engineered specifically for the pilot observation door. In the field, a compromised gasket leads to immediate combustion inefficiencies, drafts, and potential safety hazards by disrupting the sealed combustion chamber's pressure. This genuine Williams P100100 component is constructed from industrial grade refractory material designed to maintain its structural