Nordyne 661020R Orifice

The Nordyne 661020R Orifice is a precision-engineered natural gas main orifice designed for specific HVAC burner assemblies. Measuring at a .020 orifice diameter (often identified as #20 drill size), this component is critical for maintaining the correct gas-to-air ratio within the combustion manifold. As a genuine OEM replacement part, it ensures factory-spec performance for Nordyne, Intertherm, and Miller gas furnaces, including high-efficiency systems like the CMF series. This orifice features standard 1/8-27 NPT threads and a 7/16-inch hex head, allowing for straightforward installation with common technician tools. Utilizing the correct orifice sizing is essential for preventing delayed ignition or incomplete combustion, which can lead to carbon monoxide issues or heat exchanger damage. This furnace burner orifice is calibrated for natural gas applications; ensure your manifold pressure is set according to the manufacturer’s data plate when the burner is under load to verify proper BTU input and clean flame characteristics.

• Precision Metering: The #20 drill size (.020) ensures accurate BTU delivery for supported gas valves.
• OEM Compatibility: Replaces legacy part numbers including 660834, 660537, 1187210, and 118721 for streamlined inventory.
• Durable Construction: High-tolerance brass resists thermal stress and oxidation within the burner compartment.
• Standardized Fit: Features 1/8-27 NPT threading for a reliable, leak-free seal on the manifold.

Is the Nordyne 661020R compatible with LP conversion?
No, this specific orifice is calibrated for natural gas service. Propane applications require a different BTU-rated orifice to accommodate the higher energy density of liquid petroleum.

What furnace models use the #20 orifice size?
This part is commonly found in Nordyne, Miller, and Intertherm mobile home furnaces, as well as several residential split-system gas units. Always cross-reference the model number on the rating plate before installation.

Can I use this orifice if my threads look different?
This unit uses a standard 1/8-27 NPT thread. If your existing manifold port has different threading, this component will not provide a secure gas-tight seal and should not be used.

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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.