Lennox 71W43 Limit Switch 318973-401 This 100135275 burner kit is

This 100135275 burner kit is the industry standard for maintaining HVAC system reliability in demanding commercial and residential environments

Class B tolerance standards for consistent signal accuracy

Service Convenience: Manual override lever permits system flushing and manual operation without requiring electrical power

Designed to maintain precise air-fuel ratios

it requires a minimum pressure differential of 5 PSI to lift the diaphragm and maintain a fully open position

Lennox 71W43 Limit Switch 318973-401 This 100135275 burner kit isThe Lennox 71W43 Limit Switch is a critical safety component designed for precise thermal regulation within residential and commercial furnace assemblies. This OEM Lennox replacement part, also identified as the L140 30F limit control, is engineered to monitor heat exchanger temperatures and interrupt the electrical circuit if internal heat exceeds safe parameters. With a fixed 140F opening temperature and a 110F automatic reset, this switch ensures