The Watts STS20 is a thermal safety valve. It is a standalone device that is installed in solid fuel boilers and is activated when the water temperature reaches the maximum operating value. Its purpose is to remove the accumulated power in heating systems (such as pellet or wood boilers) through partial disconnection.

• The valve body is made of CW617N brass.
• It has a immersion sensor with a 145mm basket and a 1/2" A threaded connection.
• Maximum drainage capacity: 6,500 l/h at 8 bar.
• Maximum operating pressure: 10 bar.