Lochinvar & A.O. Smith 100109933 Switch 318172-701 If your unit fires but

If your unit fires but immediately trips on a freezestat error during cold starts

maintaining the same electrical ratings and physical mounting dimensions

ensuring the refrigerant pressures equalize before the compressor attempts to restart

eliminating field-modification headaches

For proper drainage and to prevent sediment interference

Lochinvar & A.O. Smith 100109933 Switch 318172-701 If your unit fires butThe Lochinvar & A. O. Smith 100109933 Blocked Inlet Switch is a critical safety component designed for high efficiency water heaters and boilers. Engineered to monitor atmospheric pressure within the combustion air intake, this OEM replacement pressure switch ensures the burner operates within safe pneumatic parameters. This specific blocked inlet switch kit is calibrated to a set point of 0. 77" Water Column, effectively detecting restricted airflow