Lochinvar & A.O. Smith 100110820 Pressure Switch

The Lochinvar & A.O. Smith 100110820 Pressure Switch is a critical safety component designed for high-efficiency gas-fired boiler and water heater systems. This 1.42" air pressure switch (1.42 in. WC) functions as a differential pressure switch, ensuring the combustion blower is generating sufficient airflow before allowing the ignition sequence to proceed. As a veteran technician knows, a failing HVAC pressure switch often results in a "no-heat" call due to the system’s failure to prove the draft. This genuine OEM replacement part is engineered to meet precise set-point tolerances, preventing flue gas spillage and ensuring reliable gas-fired water heater operation. When troubleshooting a blocked exhaust or inducer motor issue, this switch provides the necessary electrical logic to protect the internal heat exchanger and maintain energy efficiency. Designed for long-term durability in high-demand environments, it is compatible with a wide range of Power-Fin and Cyclone BTH models, making it an essential stocked item for HVAC repair professionals and mechanical contractors.

• Ensures safe combustion by verifying proper blower operation and venting pressure before ignition.
• Precise 1.42 in. WC set point eliminates nuisance tripping common with low-quality universal replacements.
• Direct OEM compatibility for Lochinvar and A.O. Smith commercial and residential units ensures a perfect fit.
• Robust internal diaphragm designed to handle the cycling demands of high-efficiency boilers.
• Simple two-wire electrical connection and sensing tube port for rapid field installation and system diagnostics.

• How do I know if this switch is failing? If your boiler stops at the prepurge cycle or throws a "Pressure Switch Open" fault code, check the sensing tubes for moisture or cracks before testing the 100110820 switch for continuity.
• Can I use a universal switch instead? Universal switches often lack the exact 1.42" WC calibration required for these specific venting systems, which can lead to unsafe operation or frequent system lockouts.
• Does this include the sensing tubes? This part number is for the pressure switch assembly itself; we recommend inspecting your existing silicone tubing for kinks or blockages during replacement.

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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.