also identified as 05

making it a critical component for restoring system balance and achieving optimal SEER ratings

When diagnosing high-limit trips or poor airflow in a Forsaire electric furnace

ensuring long-term reliability without frequent re-packing

Excess tubing should be carefully coiled and secured away from heat sources

Carrier HH12ZZ165 Limit Switch 319848-301 also identified as 05The Carrier HH12ZZ165 Limit Switch is a critical OEM safety component engineered for precision thermal monitoring in HVAC furnaces and industrial heating systems. As a fixed temperature L165F 40 limit control, this switch features a normally closed (NC) circuit designed to open on a temperature rise at its 165F set point, effectively preventing heat exchanger damage. With a 40F differential, the automatic reset engages when the internal temperature