Lennox 25W71 Gasket 326058-757 Smith models are compatible with

Smith models are compatible with this cleaning kit

providing accurate modulation with approximately 120 steps of control

making it suitable for high-pressure distribution systems

it is critical to wrap the valve body with a wet rag or use a heat-blocking putty to prevent damaging the internal seals while brazing the 1 5/8" lines

Lennox 25W71 Gasket 326058-757 Smith models are compatible withThe Lennox 25W71 Gasket is a critical OEM replacement part designed specifically for sealing the collector box cover in high efficiency Lennox furnaces. As a veteran tech knows, a compromised seal at the secondary heat exchanger leads to pressure switch trips and dangerous flue gas leakage. This precision engineered furnace collector box gasket (also indexed under 100742 01) ensures an airtight, negative pressure environment required for the draft