Carrier HH18HA130 Limit Switch 319852-301 it can be hardwired via

it can be hardwired via 24VAC (C-wire) or operated on battery power for millivolt applications

Always replace the liquid line filter drier and check the starting components

it utilizes a diaphragm-isolated spring chamber to prevent water contact with the spring

swapping in this Heil Quaker furnace part is the standard professional fix

The ASCO 8214290CSA is specifically rated for fuel gas service

Carrier HH18HA130 Limit Switch 319852-301 it can be hardwired viaThe Carrier HH18HA130 is a high precision, OEM auto limit switch designed for critical thermal regulation within residential and light commercial HVAC systems. This disc type temperature actuated switch features a specific operating range of 100 130F, functioning as a primary safety mechanism to prevent heat exchanger damage and ensure efficient blower motor cycling. As a direct replacement for the HH18HA130B, this component maintains strict 1 2" NPT