Watts 0556003 Valve

Install the Watts 0556003 (Series LF100XL) for reliable protection on water heaters and hot water storage tanks. This lead-free 3/4" T&P relief valve is engineered to automatically discharge water if system temperatures reach 210°F or if internal pressure exceeds 150 PSI. Designed as a direct updated replacement for legacy models 0066133 and LFL100XL-150-3/4, this unit features a lead-free copper-silicon alloy body and a 3-inch extension thermostat. The extended shank design is specifically optimized for modern water heaters with up to 2 inches of thick insulation, ensuring the sensing element is properly submerged in the hottest water within the top 6 inches of the tank. With a 105,000 BTU/hr capacity, it meets ASME Section IV requirements and is CSA listed to ANSI Z21.22. The unique thermo-bonded coating on the thermostat prevents mineral buildup, maintaining long-term accuracy and performance in demanding plumbing environments.

• Precise Safety Control: Dual-action protection for both excessive temperature (210°F) and pressure (150 PSI).
• Insulation Compatibility: Extended inlet shank eliminates the need for extra nipples on heaters with 2" insulation.
• Corrosion Resistance: Features a stainless steel spring and thermo-bonded thermostat coating to resist scale and mineral deposits.
• Code Compliance: ASME rated, CSA listed, and Buy American Act compliant for commercial and residential projects.
• Lead-Free Construction: Complies with all low-lead plumbing regulations for potable water systems.

Is the Watts 0556003 compatible with older L100XL models?
Yes, the 0556003 is the designated updated replacement for the L100XL-3-150, 0066133, and LFL100XL-150-3/4 series. It maintains the 3/4" NPT male inlet and female outlet connections for easy retrofitting.

What is the proper orientation for installation?
The valve must be installed so the temperature sensing element is fully immersed in the hottest water in the tank. The discharge line must be the same size as the valve outlet, pitched downward to allow for free draining, and terminate at a visible point above a floor drain.

When should this valve be replaced?
While the 0556003 is built for durability, HVAC professionals recommend inspecting the test lever annually and replacing the valve if any signs of leakage, scale accumulation, or corrosion are present, typically every 3 to 5 years depending on local water conditions.

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.