York S1-025-26392-011 SPST Rollout Switch 225°F Open 145°F Close

The York S1-025-26392-011 SPST Rollout Switch monitors burner flame path alignment inside gas-fired furnace burner compartments. Mounted directly above the burner opening, the safety switch opens its internal contacts if temperatures reach 225F in HVAC systems. Flame rollout or flue blockage redirects hot combustion gases across the switch body, breaking the main gas valve circuit to halt gas flow immediately. Automatic resetting at 145F allows normal operation after cooling, preventing furnace heat exchanger damage and supporting safe gas heating operation.