Lochinvar & A.O. Smith 100110810 Switch

The Lochinvar & A.O. Smith 100110810 Blocked Inlet Switch is a critical safety component designed for high-efficiency gas water heaters and commercial boilers. As an OEM air pressure switch, this part is engineered to monitor differential pressure within the intake system. If the sensor detects an obstruction in the air supply—caused by debris, ice, or improper venting—it immediately breaks the electrical circuit to the control board, initiating a safety lockout to prevent incomplete combustion or hazardous CO buildup. This switch is a direct replacement for legacy part numbers 195012 and 9006006215, ensuring seamless integration into existing Lochinvar Power-fin and A.O. Smith BTH 400A series units.

For technicians servicing high-efficiency condensing boilers, verifying the blocked inlet switch is a standard diagnostic step when facing "check vent" or "air switch" fault codes. This genuine A.O. Smith water heater part ensures that the combustion air blower maintains the precise static pressure required for optimal firing rates. By using a factory-calibrated safety limit switch, you ensure the appliance operates within its specified performance envelope, protecting the copper-fin heat exchanger and internal burner components from thermal stress caused by restricted airflow.

Key Benefits

• OEM Compatibility: Exact replacement for Lochinvar and A.O. Smith commercial models, including the BTH-400A series.
• System Protection: Effectively prevents operation under restricted airflow conditions to mitigate risk of equipment damage.
• Reliable Calibration: Pre-set at the factory to match the specific differential pressure requirements of the unit's intake assembly.
• Long-Term Durability: Constructed with high-grade materials to withstand the temperature and humidity fluctuations inside the air shroud.

Common Questions

How do I troubleshoot a 100110810 switch showing a fault?
Inspect the air intake pipe for blockages, check the silicone tubing for moisture or cracks, and use a manometer to verify the blower is producing the required pressure to close the switch contacts.

Is this switch interchangeable with other pressure switches?
No. Each pressure switch is calibrated to a specific set point. Using a non-OEM part or an incorrect model can lead to nuisance shutdowns or unsafe operating conditions.

What does a 'Blocked Inlet' error code mean on a Lochinvar boiler?
It indicates the 100110810 switch has detected a drop in intake pressure. This usually points to a physical obstruction in the vent termination or a failure in the combustion air blower.

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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.