The silicone diaphragm is designed to handle air and inert combustion by-products that do not degrade silicone materials

If the burner ignites but goes out after 2 to 5 seconds

Constructed with durable materials to resist scale buildup

ensuring it meets strict safety codes for potable water systems

Proper installation requires careful alignment to maintain the correct spark gap

York S1-025-27747-012 Rollout Switch The silicone diaphragm is designedThe York S1 025 27747 012 Rollout Switch is a critical safety component designed for York gas furnaces and Johnson Controls HVAC systems. Engineered to respond to flame rollout or unsafe combustion conditions, this manual reset limit switch triggers at a fixed thermal threshold of 260 degrees Fahrenheit. As a Single Pole Single Throw (SPST) control, it serves as the primary circuit interrupt for the gas valve when it detects temperatures exceeding