HVAC technicians should always verify the model and serial number on the furnace rating plate to confirm a match before beginning the repair

Key Benefits for Technicians OEM Compatibility: Exact replacement for LH33EP040 and LH33EP040A

making it a staple for commercial boiler feeds and industrial heating loops

Common Questions: What are the signs that a 30032020 control board needs replacement

Lochinvar & A.O. Smith 100111317 Pressure Switch 326010-701 HVAC technicians should always verifyThe Lochinvar & A. O. Smith 100111317 Pressure Switch is a critical OEM safety component engineered for precise airflow verification in high efficiency water heaters and boilers. This normally open air pressure switch is calibrated to a fixed set point of 0. 20" WC (Water Column), ensuring the combustion blower is generating sufficient negative pressure before the ignition sequence initiates. As a genuine 100111317 replacement part, it provides the