Lochinvar & A.O. Smith 100110715 Inlet Switch

The Lochinvar & A.O. Smith 100110715 Inlet Switch is a critical safety component designed for high-efficiency commercial and residential water heating systems. This OEM replacement part is the current updated version for the legacy 9005900215 and 193363 models. As a normally closed blocked inlet pressure switch, it monitors the air intake for obstructions. If the negative pressure at the combustion air inlet deviates from factory setpoints—often due to debris, excessive vent length, or condensate buildup—the switch opens the circuit, immediately signaling the ignition control to terminate the firing sequence. This prevents hazardous incomplete combustion and protects the heat exchanger from operational stress. Engineered for A.G.S. Cyclone BTH and SUF Series natural gas units, it ensures precise airflow proving for 150,000 to 250,000 BTU systems. This genuine Lochinvar part features a lightweight, durable housing with standard spade terminals for rapid integration into existing wiring harnesses, maintaining the integrity of the combustion blower proving circuit.

Key Benefits

• Direct OEM Logic: Provides seamless compatibility as the official successor to 9005900215, ensuring factory-spec calibration.
• Enhanced System Safety: Actively detects blocked intake conditions to prevent gas valve actuation under unsafe venting parameters.
• Nuisance Trip Reduction: High-quality internal diaphragm resists fatigue, offering reliable performance across varying static pressure conditions.
• Rugged Construction: Designed to withstand the high-temperature environments typical of commercial water heater enclosures.

Common Questions

Which models are compatible with this switch?
This switch is typically utilized in A.O. Smith Cyclone BTH 120-250 models and comparable Lochinvar high-efficiency commercial boilers and water heaters.

Does this part replace the 9005900215?
Yes, the 100110715 is the direct functional and physical replacement for part numbers 9005900215 and 193363.

What causes this switch to trip?
Common triggers include venting obstructions, excessive elbows in the air intake run, or moisture/condensate trapped in the pressure sensing tubing.

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.