Watts USG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve

1. Product Overview

The Watts USG-B-M2 Series Under Sink Guardian Thermostatic Mixing Valve is designed for commercial and residential applications. Its primary function is to mix hot and cold water at the point of use, typically under a sink, to deliver tempered water at a safe, consistent temperature. This helps to minimize the risk of accidental scalding, especially in environments with children or elderly individuals. The valve features a durable lead-free brass body construction.

An image showing the Watts USG-B-M2 thermostatic mixing valve, featuring its compact design and connection points.

2. Safety Information

• Professional Installation Recommended: Installation should be performed by a qualified plumber or technician in accordance with all local codes and regulations.
• Water Temperature: Always test the water temperature at the faucet after installation and any adjustments to ensure it is within a safe range (typically 100-110°F or 38-43°C).
• Water Pressure: Ensure that the hot and cold water supply pressures are within the operating limits specified for the valve.
• Shut-off Water Supply: Always turn off the main water supply before attempting any installation, maintenance, or repair.
• Avoid Over-tightening: Do not over-tighten connections, as this can damage the valve or fittings.

3. Product Features

• Lead-Free Brass Body Construction: Ensures durability and compliance with lead-free plumbing standards.
• Tamper-Resistant Locking Nut: Prevents accidental misadjustments of the temperature setting, maintaining consistent water temperature.
• Built-in Check Valves: Designed to prevent the migration of hot water into cold water piping and cold water into hot water piping, ensuring proper system function.
• Three-Port Application Cap: Provided for versatile installation configurations.

4. Setup and Installation

This section provides general guidelines for installing the USG-B-M2 valve. Always refer to local plumbing codes and consult a professional if unsure.

4.1 Pre-Installation

1. Turn off the main water supply to the area where the valve will be installed.
2. Drain any residual water from the hot and cold water lines.
3. Gather necessary tools: wrenches, pipe cutters (if needed), thread sealant/tape, and a thermometer.
4. Inspect the valve for any damage before installation.

4.2 Connecting the Valve

1. Identify the hot water inlet, cold water inlet, and mixed water outlet ports on the valve. These are typically marked.
2. Connect the hot water supply line to the hot inlet port using appropriate compression fittings. Ensure a secure, leak-free connection.
3. Connect the cold water supply line to the cold inlet port using appropriate compression fittings.
4. Connect the mixed water outlet port to the faucet supply line.
5. For three-port applications, ensure the provided cap is correctly installed on the unused port if applicable.

4.3 Post-Installation Checks

1. Slowly turn on the main water supply.
2. Check all connections for leaks. Tighten gently if necessary.
3. Open the hot water faucet to purge air from the lines.
4. Proceed to the Operating Instructions section to set the desired temperature.

5. Operating Instructions

The USG-B-M2 valve is designed to maintain a consistent mixed water temperature. Initial adjustment is typically done during installation.

1. Initial Temperature Setting: With the water flowing from the faucet, use a thermometer to measure the mixed water temperature.
2. Adjusting Temperature: The valve features a tamper-resistant locking nut. To adjust the temperature, loosen the locking nut. Rotate the adjustment stem (usually a cap or screw) to increase or decrease the mixed water temperature.
3. Secure Setting: Once the desired safe temperature is achieved (e.g., 105°F or 41°C), tighten the tamper-resistant locking nut to secure the setting.
4. Verify Temperature: Always re-verify the temperature with a thermometer after making adjustments.

6. Maintenance

Regular maintenance ensures optimal performance and longevity of your thermostatic mixing valve.

• Periodic Inspection: Annually inspect the valve and connections for any signs of leaks, corrosion, or damage.
• Temperature Verification: Periodically check the mixed water temperature with a thermometer to ensure it remains at the desired safe setting. Readjust if necessary following the operating instructions.
• Check Valve Function: Ensure the built-in check valves are functioning correctly. If there are issues with hot water migrating to cold lines or vice-versa, the check valves may need inspection or replacement.
• Cleaning: If water quality is poor, sediment or mineral buildup may affect valve performance. Consult a professional for cleaning or servicing if flow or temperature control is compromised.

7. Troubleshooting

If troubleshooting steps do not resolve the issue, contact a qualified plumbing professional.

8. Specifications

• Model Number: USG-B-M2
• Material: Brass, Bronze
• Exterior Finish: Bronze
• Inlet Connection Type: Compression
• Outlet Connection Type: Compression
• Number of Ports: 4
• Outlet Connection Size: 0.38 Inches (3/8 Inch)
• Specification Met: ASSE 1070
• Item Weight: 12.3 ounces
• Package Dimensions: 3.82 x 3.54 x 2.52 inches
• UPC: 098268548471

9. Warranty and Support

For detailed warranty information and technical support, please contact Watts customer service directly or visit their official website. Keep your purchase receipt as proof of purchase for any warranty claims.

Watts Official Website: www.watts.com