Watts 0559103 Mix Valve

The Watts 0559103, also identified as the LF1170M2-US, is a high-performance 3/4 inch thermostatic mixing valve designed for precision temperature control in domestic water applications. Built with a lead-free brass body to meet stringent potable water standards, this valve utilizes a paraffin-based actuator to maintain a stable mixed water temperature. It features a wide temperature adjustment range of 90°F to 160°F, making it suitable for both point-of-source and larger distribution systems. The integrated check valves and stainless steel strainers protect against cross-flow and debris, ensuring the longevity of the mixing valve assembly. For technicians, the union solder connections simplify the installation process, providing a robust seal in high-pressure hydronic or domestic plumbing loops. Whether you are performing a water heater tempering valve replacement or a new system install, this unit provides the thermal stability required to prevent scalding while allowing for higher storage temperatures to mitigate bacterial growth.

Key Benefits

• Lead-free construction complies with NSF/ANSI 372 and 61 requirements for safe potable water delivery.
• Dual check valves prevent migration of hot and cold water between supply lines.
• Solid paraffin actuator ensures rapid response to pressure and temperature fluctuations.
• Union connections allow for easy removal and servicing without cutting the service lines.
• Locking temperature adjustment prevents unauthorized tampering with the set point.

Common Questions

Is the Watts 0559103 compatible with radiant heating systems?
Yes, this 3/4" mixing valve is frequently used in radiant floor heating to maintain low-temperature loops, provided the flow rates match the system design.

How do I adjust the outlet temperature?
Remove the protective cap and turn the adjustment handle while monitoring a downstream thermometer to reach your target temperature between 90°F and 160°F.

What is the maximum working pressure for this valve?
The unit is rated for a maximum pressure of 150 psi, though it is optimized for typical residential and light commercial plumbing pressures.

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.