Lochinvar & A.O. Smith 100294585 Pressure Switch

When you're out on a service call and a high-efficiency Lochinvar boiler or A.O. Smith water heater isn't firing, the 100294585 Pressure Switch is often the technical culprit. This 0.68" WC pressure switch is a critical safety component designed to calibrate the air-to-fuel ratio by monitor differential pressure within the combustion chamber. As a direct OEM replacement part for the discontinued 100166118 and PRS20024, it ensures the inducer motor is moving enough air to safely vent flue gases before the ignition sequence begins. Built with a manual-reset design and rated for 120/240 VAC @ 15A, this HVAC pressure switch offers the precise 0.68-inch water column set point required for internal safety loops. It is compatible with a wide range of commercial and residential models, including the Lochinvar CHL and CHN series. Using this genuine 100294585 component ensures your repair meets exact manufacturer specs for reliable inducer proving and long-term system performance.

• Direct OEM Compatibility: Engineered as the exact 0.68" WC replacement for part numbers 100166118 and PRS20024, eliminating the risk of incorrect set-point trips.
• Precise Pressure Sensing: Specifically factory-calibrated to 0.68 inches of water column to ensure the combustion blower is operating within safe margins.
• Wide Application Range: Fits over 60 different Lochinvar and A.O. Smith models, making it a versatile stock item for boiler and water heater maintenance.
• Industrial Build Quality: Features a robust diaphragm and electrical contacts rated for 15A to handle standard control circuit voltages without premature failure.

How do I verify if the 100294585 pressure switch is bad?

First, check for restrictions in the flue or condensation in the sensing lines. If the inducer is running but the switch remains open, use a manometer to verify the actual draft. If the draft exceeds 0.68" WC and the switch still fails to close its contacts, the internal diaphragm or electrical contact has failed, necessitating a replacement.

Is the 100294585 compatible with different water column ratings?

No. Pressure switches are safety-critical components. You should never substitute a 0.68" WC switch with a different rating, as it can lead to unsafe combustion conditions or frequent nuisance lockouts.

What models does this part typically fit?

This switch is commonly found in Lochinvar CHL (0402-1262) and CHN (0402-1262) series heating boilers, as well as several A.O. Smith high-efficiency water heating units.

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.