Lennox 42J04 Limit Switch 30-amp magnetic contactor designed as

30-amp magnetic contactor designed as a reliable field swap for problematic switches in residential and light commercial condensers

ensuring precise equal percentage flow characteristics in demanding hydronic and steam applications

or blocked return air grilles that cause heat to build up beyond the 155°F threshold

System Restoration: Eliminates internal leakage and restores accurate linear flow characteristics in aging HVAC systems

Lennox 42J04 Limit Switch 30-amp magnetic contactor designed asThe Lennox 42J04 Limit Switch is a critical OEM replacement part designed for high limit thermal protection in residential and commercial HVAC systems. Engineered to maintain safe operating parameters, this 135 175F Auto Limit Switch features an automatic reset mechanism that interrupts the heating circuit if internal plenum temperatures exceed the 175F threshold, preventing heat exchanger damage and ensuring system safety. This fixed temperature