Watts 0556004 Valve

The Watts 0556004 (Model LLL100XL-150) is a specialized 3/4" Temperature and Pressure Relief Valve designed specifically for modern high-efficiency water heaters and storage tanks. For technicians dealing with the "thick insulation" challenge, this model features an extra extended shank that accommodates up to 3 inches of tank insulation, effectively eliminating the need for additional extension nipples that can compromise seal integrity. This lead-free copper silicon alloy valve is rated for 105,000 BTU/hr and is factory-set to trip at 150 psi or a maximum temperature of 210°F. Internally, the thermostat probe is protected by a unique thermo-bonded coating to prevent mineral buildup, ensuring long-term response accuracy. Built for professional hot water heater safety, it carries ASME and CSA certifications, meeting ANSI Z21.22 standards for reliable discharge performance. This unit serves as the direct 0556004 replacement for older or non-lead-free models including 0066446 and LFLLL100XL-150-3/4.

• Extended Inlet Shank: Engineered specifically for heaters with up to 3" of insulation, removing the complexity of external piping extensions.
• High BTU Capacity: Rated for systems up to 105,000 BTU/hr, providing versatile protection across residential and light commercial applications.
• Corrosion Resistance: Features a lead-free copper alloy body and a stainless steel spring to withstand aggressive water conditions.
• Proven Safety Standards: Fully ASME rated and CSA listed to ensure compliance with strict local plumbing and building codes.
• Thermo-Bonded Coating: The thermostat element is shielded against scaling and calcification to maintain precise temperature relief at 210 degrees Fahrenheit.

Common Questions from Contractors

Is the Watts 0556004 compatible with my tank?
This valve is designed for 3/4" NPT connections. If your water heater uses extra-thick foam insulation (up to 3"), this extra extended shank T&P valve is the correct specification to reach the tank tapping without additional fittings.

What is the difference between the LLL100XL and standard 100XL models?
The "LLL" designation indicates the maximum shank extension length within the 100XL series. While a standard Watts T&P relief valve may have a short length, the LLL100XL provides the necessary reach for highly insulated modern vessels.

Can I use this for a 150,000 BTU heater?
No. This specific model (0556004) is rated for a maximum of 105,000 BTU/hr. Always verify your heater’s BTU rating on the nameplate; if your unit exceeds this capacity, you must step up to a higher-rated relief valve to maintain safety compliance.

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.