The non-PCB

moisture-resistant round metal canister

Look for visible cracking

Standardized Fit: 12789 MARS specifications match most OEM requirements for 45+7

or an outdoor fan motor that hums but refuses to spin

Lennox 42J03 Limit Switch The non-PCBThe Lennox 42J03 Limit Switch is a critical safety component designed for precise thermal regulation within residential and commercial HVAC systems. This genuine OEM replacement part, also identified as part number 42J0301, features a fixed temperature range of 150 190F with an automatic reset function. As a veteran grade furnace high limit switch, it monitors the plenum temperature and breaks the electrical circuit to the gas valve if overheating is