Lochinvar & A.O. Smith 100208390 Pressure Switch

The Lochinvar & A.O. Smith 100208390 Pressure Switch is a critical safety component engineered for precise draft proving in high-efficiency commercial and residential boilers and water heaters. As a veteran-grade OEM replacement pressure switch, this part is built to detect specific pressure differentials, ensuring the inducer motor establishes a safe venting environment before the ignition sequence initiates. This specific model is a direct cross-reference for part numbers PRS2006 and PRS2006K, maintaining exact factory specifications to ensure seamless HVAC part compatibility for field technicians and contractors.

Constructed for long-term reliability in demanding thermal environments, the 100208390 features a highly sensitive diaphragm and a snap-acting internal switch that prevents furnace short cycling caused by fluctuating flue pressures. When troubleshooting an A.O. Smith 100208390, technicians should verify the set point using a calibrated manometer to ensure the venting system meets the appliance’s specific air-to-fuel ratio requirements. By utilizing a genuine Lochinvar burner pressure switch, you eliminate the risks associated with generic aftermarket alternatives, ensuring the system’s pressure safety circuit operates according to the original engineering design.

Key Benefits for HVAC Professionals

• Direct OEM Match: Fully replaces 100208390, PRS2006, and PRS2006K without the need for mounting box modifications.
• Draft Verification Accuracy: High-precision set points ensure the vacuum is maintained for safe combustion and efficient venting.
• Reduced Troubleshooting Time: Reliable terminal connections and a rugged housing design help technicians quickly rule out switch failure during ignition sequence diagnostics.
• Universal Application: Compatible with a wide range of Lochinvar and A.O. Smith high-efficiency gas units.

Common Questions

How do I confirm if the 100208390 switch is at fault for a lockout?
Perform a continuity test with your multimeter while the inducer is running. If the inducer reaches full RPM but the switch fails to close, or if the switch is stuck closed when the motor is idle, it must be replaced to restore proper safety timing sequence.

Can this pressure switch be used in systems with high-altitude kits?
Yes, provided the specific unit’s manual specifies part 100208390. Always check the atmospheric pressure ratings, as high-altitude adjustments typically require parts calibrated for thinner air densities.

Is there a difference between the 100208390 and the PRS2006?
No, they are technically identical. The 100208390 represents the updated manufacturer part number used across Lochinvar and A.O. Smith inventory systems.

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.