Lochinvar & A.O. Smith 100074672 Manifold Assembly

The Lochinvar & A.O. Smith 100074672 Manifold Assembly is a critical OEM replacement component for high-efficiency natural gas tankless water heaters. This integrated unit combines a precision-engineered natural gas manifold with a dedicated gas valve assembly to regulate fuel delivery and maintain stable combustion across varying load demands. Whether you are servicing a residential or commercial system, using the correct Lochinvar gas manifold is essential for maintaining factory-specified manifold pressure and ensuring the flame rectification circuit operates within tolerances. Designed specifically for the T-H3 series gas valve and TK-540P series units, this assembly addresses issues such as gas flow inconsistencies, burner ignition failures, or valve block malfunctions. By installing this genuine OEM replacement part, technicians ensure the pressure drop and BTU input remain consistent with the original manufacturer specifications, preventing potential soot buildup or overheating associated with aftermarket alternatives.

Key Benefits for Technicians:

• Direct Compatibility: Drop-in replacement for A.O. Smith replacement parts and Lochinvar tankless units, including T-H3-DV, T-H3-OS, and TK-540P models.
• Integrated Design: Replaces both the manifold and gas valve in one unit, reducing diagnostic time and potential leak points.
• Regulatory Compliance: Engineered for natural gas applications, meeting strict safety and efficiency standards for high-output condensing and non-condensing heaters.
• System Integrity: Restores peak performance by ensuring precise gas modulation and burner distribution.

Common Questions:

Is this manifold assembly compatible with propane (LP) units?
No, the 100074672 is strictly designed for Natural Gas (NG) configurations. High-pressure LP systems require a different orifice sizing and valve calibration.

Does this assembly include the gas valve mounting hardware?
This is a comprehensive manifold with gas valve assembly, though it is professional practice to inspect and reuse or replace mounting gaskets and O-rings to ensure a gas-tight seal upon installation.

What are the signs that a gas manifold assembly needs replacement?
Common indicators include persistent error codes related to gas solenoids, inconsistent manifold pressure during high-fire modulation, or visible corrosion on the manifold tubes that could lead to gas leaks.

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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.