This typically indicates an obstruction in the venting system

Technicians should look for visible cracks in the ceramic or insulation

Look for physical signs such as a bulged top (tripped internal protector) or oil leaks

What is the difference between K16RA-60 and K16RA-60H

York S1-2940-3161 Switch Els PW 17895 This typically indicates an obstructionThe York S1 2940 3161 Fan and Limit Switch is a critical OEM replacement component designed for precise thermal regulation within HVACR systems. This reliable furnace limit control is factory calibrated with a 105F opening temperature and a 120F closing temperature (105Op 120Cl), ensuring the blower fan cycles correctly to maximize airflow efficiency and prevent heat exchanger overheating. As an HVAC high limit switch, it provides an essential safety