The Reznor 121598 Valve is a critical OEM replacement part designed for integration with intermittent pilot ignition systems in industrial and commercial unit heaters. This Honeywell VR8304M2808 gas control features a straight-through body pattern with 1/2-inch NPT inlet and outlet ports, engineered to manage natural gas delivery in demanding HVAC applications. Operating on a 24 VAC circuit with a 0.5A to 0.7A current draw, the valve includes a servo-operated pressure regulator that is factory-set at 3.5 inches WC but remains adjustable from 3 to 5 inches WC to ensure precise manifold pressure during commissioning. This combination gas control incorporates two automatic operators and a manual shut-off, providing high-capacity flow up to 240 ft³/hr. Technicians should verify the pilot tube connection (standard 7/16-inch thread) and ensure the existing burner configuration matches the single-stage firing rate designated for the RZ121598. This robust valve maintains reliable performance across an ambient temperature range of -40°F to +175°F, making it suitable for unconditioned mechanical spaces. Key Benefits Ensures precise natural gas pressure regulation with a 3.5" WC adjustable servo regulator for consistent burner performance. Designed for intermittent pilot furnaces, providing a direct fit for Reznor HVAC equipment and reducing field modification time. Built with a dual automatic valve design to meet safety standards for automatic shut-off in industrial environments. Versatile mounting capability allows installation from 0 to 90 degrees in any direction from the upright position. Standard 1/2-inch NPT connections and 1/4-inch male quick-connect terminals simplify replacement in existing gas trains. Common Questions Is the VR8304M2808 compatible with propane (LP) systems? This specific model is configured for natural gas. While some VR8304 series valves support conversion, you must use the manufacturer-approved LP conversion kit and verify the regulator spring requirements before field modification. What should I check if the valve fails to open on a call for heat? Verify 24 VAC is reaching the MV/PV terminals from the ignition module. If voltage is present and the pilot flame is proven but the main burner fails to ignite, ensure the manual gas cock is in the "ON" position and the inlet pressure meets the minimum 5" WC requirement. Does this valve replace the older Honeywell VR8204 or VR8300 series? The 121598 is a high-capacity replacement often used where higher BTU ratings are required. Always cross-reference your specific heater model and serial number, as port sizes and electrical ratings vary between the VR8200 and VR8300 series. 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.
