If your media is compatible with FKM

and thermostats without risk of chatter or premature component failure

12" insertion length to monitor internal plenum temperatures effectively

This specific sizing is determined by the furnace's BTU rating and the type of gas used (Natural Gas vs

Look for yellow or flickering flames

Carrier HH18HV131 Limit Switch If your media is compatibleThe Carrier HH18HV131 Limit Switch is a critical OEM replacement part designed for precise thermal regulation in Carrier, Bryant, and Payne HVAC systems. Engineered as a high limit safety device, this automatic reset switch features a 130 30 degree operating range, meaning it trips at 130F to prevent furnace overheating and automatically resets when temperatures drop by 30F. Reliable thermal protection is essential for preventing damage to the heat