Description
Watts 100XL-3-150 Temperature & Pressure Relief Valve
The Watts 0556000 100XL-3-150 is a 3/4″ temperature and pressure (T&P) relief valve engineered to provide dependable overpressure and overtemperature protection for residential and light commercial water heaters and hydronic heating systems. Designed and manufactured by Watts — a trusted name in flow control and safety — this valve automatically opens to discharge water when system temperature or pressure exceeds safe operating limits, protecting equipment and occupants from potentially dangerous conditions.
Key Specifications
- Model: 100XL-3-150
- SKU: 0556000
- Connection Size: 3/4″
- Temperature Rating: 210°F
- Pressure Rating: 150 PSI
- BTU/hr Relief Capacity: 100,000 BTU/hr
- Valve Type: Temperature & Pressure (T&P) Relief Valve
Features & Benefits
- Dual-function protection against both excess temperature (210°F) and excess pressure (150 PSI)
- 100,000 BTU/hr discharge capacity suitable for residential water heaters and hydronic boilers
- 3/4″ connection size for straightforward installation on standard water heater and boiler ports
- Watts 100XL series construction for long-term reliability and code compliance
- Automatic reset design — valve reseats once safe operating conditions are restored
- Corrosion-resistant materials for extended service life in potable water and hydronic applications
Applications
- Residential and light commercial water heaters
- Hot water boilers and hydronic heating systems
- Any pressurized hot water vessel requiring ASME/ANSI-compliant T&P protection
Why Choose Watts?
Watts Water Technologies has been a global leader in plumbing, flow control, and water quality products for over a century. The 100XL series T&P relief valves are built to meet industry safety standards, giving contractors and homeowners confidence that their systems are protected against thermal and pressure runaway events.









