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Watts New Generation of Master Tempering Valves

Series N170 master tempering valves thermostatically blend hot and cold water ensuring safe delivery throughout hot water distribution systems in commercial, institutional and industrial facilities. Five brand new models (3/4 to 2 inch) are designed to meet a broad range of capacity and budget requirements.

The N170 is listed to ASSE 1017 and replaces the current Series N170-M2. The N170 has also earned CSA B125.3 compliance through IAPMO and carries the cUPC seal.

Although the N170 has been re-engineered inside and out, it maintains the exact rough-in dimensions of its Series M2 predecessor, making direct replacement trouble-free. The Series M3 is also offered with checkstops (with filters) for new installations.

Series N170 Sizing Tool Size Now


  • ASSE 1017 listing and CSA B125.3 compliance ensure safe, consistent
    performance over time.
  • Broader temperature range eliminates the need for low temperature
    models. The M3 series operates safely over a range of 90 - 180°F (32 - 82°C)
  • Vastly improved low flow control (as low as 3.0 gpm) for applications
    where minimum flow performance is critical.
  • Approach temperature (hot water inlet – mixed outlet) of 5°F (2.8°C)
    provides maximum mixed outlet temperature for installations where
    hot water is generated at lower temperatures.
  • Now offered with check stops and integrated filters for new
    installations as well as without for retrofit installations.

Engineered from the Inside for Superior Performance and Reliability

Multi-Directional Mounting

The new Series N170 features multi-directional mounting which allows it to be mounted as shown without affecting performance. This provides greater installation options for new projects. Rotatable, union checkstops (optional) can be rotated 360º as well.

More Information

Product Brochure

Click here to download the
N-170 Product Brochure

Specification Sheets
Installation Instructions
Cross Reference Table
Sizing Tool

Size Master Tempering Valves for Hot Water Distribution Systems

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Additional Information

Danger – Scalding Lurks!

Every year, thousands of people suffer serious thermal shock or scalding injuries in their bathtubs, sinks and showers.

Click here for informative resources to help you protect against these dangers.

Learn About

Thermostatic Mixing Valves

Every year thousands suffer injuries as a result of hot water scalding and thermal shock injuries. Thermostatic mixing valves protect against these dangers.

To learn more about thermostatic mixing valves and how they work, click here.