Supco SLS300 1/2″ Bimetal Rollout Limit Switch, 300°F Cut-out, Auto Reset

Description

Supco SLS300 Bimetal Rollout Limit Switch Overview

The Supco SLS300 is a 1/2″ bimetal rollout limit switch engineered to protect furnaces and heating equipment from dangerous heat rollout conditions. With a fixed 300°F cut-out temperature and a fixed 250°F cut-in temperature, this switch delivers precise, repeatable thermal protection without the need for manual calibration. Its open-on-rise switch action immediately interrupts the circuit when temperatures exceed the safe threshold, helping prevent heat exchanger damage, equipment failure, and potential fire hazards.

Key Features

• Fixed 300°F (149°C) cut-out temperature for reliable high-limit protection
• Fixed 250°F (121°C) cut-in temperature for automatic circuit restoration
• Open-on-rise switch action interrupts circuit when temperature exceeds set point
• Auto reset operation — restores circuit automatically once temperature drops to cut-in point
• 1/2″ bimetal sensing element for accurate, responsive temperature detection
• Designed for rollout limit switch applications in residential and light commercial furnaces

Product Specifications

• Brand: Supco
• Model/SKU: SLS300
• Cut-out Temperature: 300°F (Fixed)
• Cut-in Temperature: 250°F (Fixed)
• Switch Action: Open on Rise
• Reset Type: Auto Reset
• Sensing Element Size: 1/2″
• Sensing Element Type: Bimetal
• Application: Rollout Limit Switch

Application & Installation

The SLS300 is a direct replacement rollout limit switch suitable for a wide range of gas furnaces. It is typically mounted near the burner assembly to detect abnormal flame rollout — a condition where flames escape the heat exchanger and pose a serious safety risk. When rollout is detected, the switch opens the control circuit, shutting down the burner. Once temperatures return to the safe cut-in threshold of 250°F, the auto reset function restores normal operation without requiring manual intervention. Always verify compatibility with the OEM specifications of the equipment being serviced before installation.