Lochinvar & A.O. Smith 100110783 Pressure Switch

The Lochinvar & A.O. Smith 100110783 Pressure Switch is a critical safety component engineered for high-efficiency commercial and residential boilers and water heating systems. As a blocked inlet pressure switch, this OEM replacement part is calibrated to monitor airflow and combustion exhaust conditions. If the venting system becomes obstructed or the inducer motor fails to maintain the required pressure differential, this switch breaks the electrical circuit to the ignition control module, preventing hazardous operation. This specific HVAC pressure sensor is built to maintain tight tolerances and is commonly utilized in GDHE-50 series units and various high-recovery water heaters.

When diagnosing a system that failed to ignite, check for continuity across the 100110783 switch terminals while the blower is energized. This part replaces legacy numbers 193356 and 9005972215. Field technicians should verify the air tube integrity and ensure there is no moisture buildup in the sensing lines, as this is a frequent cause of premature tripping. Utilizing an original equipment manufacturer part ensures your installation maintains its UL/CSA certification and operates within the performance parameters established by Lochinvar and A.O. Smith.

• Ensures combustion safety by monitoring for blocked venting or inlet air restrictions.
• Direct OEM replacement for seamless fitment in A.O. Smith and Lochinvar technical assemblies.
• Rugged construction designed to withstand high-cycle operations in demanding HVACR environments.
• Precise set-points prevent unnecessary nuisance tripping while protecting internal heat exchangers.

• How do I know if my 100110783 switch is bad? If your boiler cycles the inducer but never proceeds to ignition, and you measure 24V at the input but not the output of the switch, it is likely failed or sensing a genuine vent blockage.
• Can I use an adjustable universal switch instead? No. Lochinvar 100110783 features a factory-calibrated set-point specifically for the GDHE-50 airflow curve. Using a different switch can lead to unsafe operation or frequent system lockouts.
• What does this switch replace? This component is the verified replacement for part numbers 193356 and 9005972215.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.