Lennox 74W77 Limit Switch R-410A or weak airflow at the

or weak airflow at the registers

Can I use this kit for a through-the-roof installation

this single-stage SPDT control provides a wide regulation range from -40°F to 212°F

ensuring your defrost schedules remain intact during transient power loss or site maintenance

Whether you are addressing uneven cooling or performing a blower motor pulley replacement

Lennox 74W77 Limit Switch R-410A or weak airflow at theThe Lennox 74W77 Limit Switch is a critical OEM safety component engineered for precise thermal regulation within Lennox furnaces and air handlers. This L155 30F limit switch is calibrated to open at 155F and automatically reset when the temperature drops by 30F, preventing heat exchanger damage and ensuring safe operational cycles. Designed as a direct Lennox 74W77 replacement, this high limit control utilizes a bimetal sensing element to monitor