Watts Tempering Valve 20mm


Used in hot water supply systems to mix hot and cold water to a controlled outlet temperature, reducing the risk of exposure to excessively hot water.

Features & Benefits

Features and Benefits

  • Used on high pressure hot water systems
  • Valve can be installed in any orientation
  • Dual check valves, suitable for ring main applications
  • Failsafe shutdown in the event of failure of hot and cold supplies
  • High quality DR brass body
  • 100% tested
  • Complies with NZ building code (G12)



  • Nominal size 20mm
  • Maximum static supply pressure 1400 kPa
  • Maximum dynamic supply pressure 500 kPa
  • Factory set at 53°C, can be adjusted between 35°C and 60°C
  • Connections 20mm male, ¾ “ BSP
  • Hot and cold check valves for ring main installations

Product Codes

TV20C     20mm Commercial Tempering Valve (Non-return on both inlets)

Installation & Servicing


  • Valve must be fitted by a qualified plumber
  • Flush lines before installation
  • Valve may be fitted in any orientation
  • Valve must be protected by a line strainer
  • Connections are H (hot inlet), C (cold inlet) and OUT (tempered water delivery)
  • Do not apply heat near valve during installation
  • Do not install valve directly into outlet of cylinder
  • 1m MINIMUM copper pipe from cylinder to tempering valve is a requirement of G12

  • Remove cap, use a screwdriver to adjust to the desired temperature. To increase, turn anti-clockwise.
  • To decrease, turn clockwise. Check outlet temperature required by local authorities with a calibrated thermometer.



  • Complies with NZBC Clause G12 (2014)
  • Complies with NZS 4617: 1989

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