Lennox 47K18 400°F Manual Reset SPST Rollout Switch

Description

Lennox 47K18 Rollout Switch Overview

The Lennox 47K18 is a manual reset rollout switch engineered to protect furnaces and heating systems from the hazards of flame rollout. When burner flames extend beyond their intended combustion area, this switch detects the abnormal heat event and immediately interrupts the circuit, shutting down the system before damage or danger can occur. Once tripped, the switch requires a manual reset, ensuring a qualified technician inspects and resolves the root cause before the system is returned to service.

Key Features

• Trip temperature: 400°F (204°C) — designed to respond to flame rollout events
• Manual reset operation — requires technician intervention before system restart
• SPST (Single Pole, Single Throw) configuration for straightforward circuit interruption
• Direct OEM replacement for compatible Lennox furnace models
• Provides critical overheat and flame rollout protection
• Helps prevent heat exchanger damage, carbon monoxide risk, and fire hazards

How Rollout Switches Work

Rollout switches are safety devices mounted near the burner assembly of a furnace. Under normal operation, flames are contained within the heat exchanger. If a blockage, cracked heat exchanger, or improper combustion causes flames to roll out toward the burner compartment, the rollout switch senses the elevated temperature and opens the circuit. The manual reset design of the 47K18 prevents automatic restart, protecting both the equipment and building occupants until the underlying issue is properly diagnosed and corrected.

Application

• Replacement rollout switch for Lennox furnaces and heating equipment
• Suitable for residential and light commercial HVAC applications
• Compatible with systems requiring a 400°F trip-point manual reset safety switch

Why Choose the Lennox 47K18

Using a genuine Lennox OEM replacement switch ensures proper fit, reliable trip accuracy, and compliance with original equipment specifications. Substituting non-OEM components can compromise safety performance and may void equipment warranties. The 47K18 delivers the dependable protection your Lennox system was designed to rely on.