Lochinvar & A.O. Smith 100171558 Gas Smart Valve

The Lochinvar & A.O. Smith 100171558 Gas Smart Valve is a critical direct-drive control component designed for high-efficiency LP gas heating systems. Operating on a 24V circuit with a standard 1/2" NPT connection, this SmartValve system provides integrated domestic hot water and space heating control by combining gas flow regulation and ignition sequence management into a single modular unit. This part is a direct manufacturer replacement for the discontinued Lochinvar VAL1171 and is 100% identical in form, fit, and function, requiring no manifold modifications or rewiring for a standard swap.

For field technicians, the 100171558 gas control valve simplifies troubleshooting by utilizing an internal microprocessor to monitor combustion parameters and pilot safety. In liquefied petroleum (LP) applications, maintaining precise manifold pressure is essential; this valve is factory-calibrated to handle the specific gravity and BTU content of propane, ensuring clean ignition and consistent burner performance. Whether you are servicing residential A.O. Smith water heaters or Lochinvar boilers, this OEM replacement gas valve restores the system to factory specifications, preventing common issues like intermittent pilot rollout or failure to prove flame.

• Direct Replacement: Fully interchangeable with VAL1171, ensuring a drop-in fit for existing 1/2" gas lines.
• Integrated Logic: Combines the functions of a traditional gas valve and ignition control for reduced failure points.
• Optimized for LP: Specifically engineered for propane (LP) gas systems to ensure correct pressure regulation.
• Enhanced Diagnostics: Smart technology helps identify system faults quickly, reducing diagnostic time on the job site.
• OEM Reliability: Genuine Lochinvar and A.O. Smith part for guaranteed compatibility with specified boiler and water heater models.

Is the 100171558 compatible with natural gas systems?
No, this specific model is calibrated for LP gas (Propane). Using an LP valve on a natural gas system without a proper conversion kit can lead to hazardous combustion conditions and equipment damage.

What is the difference between 100171558 and VAL1171?
There is no functional difference. VAL1171 is the legacy part number, and 100171558 is the current manufacturer identification. They are technically identical components.

What are the common symptoms of a failing Smart Valve?
Technicians often report ignition failure, short cycling, or a "no hot water" condition. If the 24V signal is present at the valve but the internal operator fails to open or the pilot fails to energize, a replacement is typically required.

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.