The Watts 0556002 LL100XL is a 3/4″ Temperature and Pressure (T&P) Relief Valve engineered to provide dependable safety protection for residential and light commercial water heaters and hydronic systems. Rated at 150 PSI and 100,000 BTU/hr, this valve automatically opens to safely discharge excess pressure or temperature, preventing dangerous over-pressurization and protecting your equipment and building occupants.
Key Features
- 3/4″ connection size for easy installation on standard water heaters and hydronic systems
- 150 PSI pressure rating for robust overpressure protection
- 100,000 BTU/hr relief capacity to handle high-demand applications
- Automatic actuation — opens on excess temperature or pressure, reseats when conditions normalize
- Durable construction built to meet the demands of daily HVAC and plumbing service
- Watts LL100XL series — a trusted name in relief valve technology
Application
- Residential and light commercial water heaters
- Hydronic heating systems and boilers
- Anywhere T&P protection is required per code
Specifications
- Brand: Watts
- Model: LL100XL
- SKU: 0556002
- Inlet/Outlet Size: 3/4″
- Pressure Rating: 150 PSI
- BTU/hr Rating: 100,000 BTU/hr
- Valve Type: Temperature & Pressure (T&P) Relief Valve








