White-Rodgers 37C73U-174 Valve

The White-Rodgers 37C73U-174 is a direct replacement natural gas water heater valve engineered for precision temperature control and reliable pilot safety in residential systems. This gas water heater thermostat control features a 1-1/4 inch shank and integrates a 1/2-inch NPT inlet with a 1/2-inch inverted flare outlet, making it a drop-in solution for many A.O. Smith and Bradford White applications. Designed for a natural gas water heater, it operates within a 70°F to 155°F temperature range and maintains a fixed manifold pressure of 5.0" W.C. for both the main burner and pilot. The built-in Energy Cut Off (E.C.O.) high-limit switch ensures the system shuts down if water temperatures exceed safe thresholds, while the 1/4 inch compression pilot connection simplifies line installation. For contractors tackling a White-Rodgers 37C73U-174 replacement, this unit offers a robust gas cock with a safe lighting feature and an internal filter to protect the pilot orifice from debris. Verify the 4-1/2 inch bulb insertion length to ensure proper sensing orientation within the tank.

Key Benefits

• Compatible with specific A.O. Smith and Bradford White gas valve configurations, replacing the 37C73U-652 and 186300-000 models.
• Features a factory-set 5.0" W.C. regulator for consistent burner performance without the need for field adjustments.
• Integrated Energy Cut Off (E.C.O.) non-cycling high limit provides mechanical over-temperature protection.
• Includes a manifold pressure tap to allow for fast and accurate diagnostic testing during commissioning.
• Clean 1/2-inch NPT x 1/2-inch inverted flare ports allow for a leak-free water heater gas valve installation.

Common Questions

How do I know if the 37C73U-174 is compatible with my water heater?
This valve is specific to natural gas applications only and is primarily used as an OEM replacement for A.O. Smith part number 186300-000. You should check the shank length (1-1/4") and the bulb insertion length (4-1/2") against your existing control to ensure a proper fit.

What should I do if the pilot light won't stay lit?
Standard troubleshooting for this White-Rodgers gas control includes checking the 1/4" compression pilot connection and ensuring the thermocouple is fully seated and generating sufficient millivoltage. If the pilot fails, the automatic shut-off feature will engage for safety.

Can this valve be used for Propane (LP) conversion?
No, the 37C73U-174 is factory-calibrated for natural gas and features a fixed regulator. Attempting to use this on an LP system is dangerous and will cause improper burner operation.

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.