What is a Thermostatic Control Valve?
The purpose of a Thermostatic Control Valve (TCV) is to regulate the temperature of water before it reaches your sink or bathtub faucet. A TCV ensures constant temperature of water by blending hot water with cold water to prevent scalding or thermal shock. There are circumstances where inlet temperature and pressure are inconsistent and pose potential danger to a bather. Responding to these variations in temperature and pressure is the only way to ensure maximum bather safety.
How a Thermostatic Control Valve Works
Before the use of tempered water in a bathtub, outlet temperature is adjusted by a thermostat in the mixing chamber of the valve. The thermostat automatically positions a seat assembly which controls the flow of hot and cold water supplied to the mixing chamber. If the mixed outlet temperature decreases, the cold water inlet port gets blocked by the seat assembly, which is adjusted by the contraction of the thermostat. On the contrary, if the mixed outlet temperature increases, the hot water inlet port gets blocked by the seat assembly, which is adjusted by the expansion of the thermostat. In both cases, outlet water temperature is fixed at a set point.
Advantages of a Thermostatic Control Valve
Safety is one of our greatest concerns and that is why we use a Thermostatic Control Valve to regulate temperature output. Some plumbers and contractors recommend that home owners and installers reduce the temperature of their water heaters to save energy and prevent scalding. This isn’t a recommendation we would give, and would guide you away from doing so. According to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE®), water in a home system needs to be stored at 140°F (60°C) otherwise Legionella disease bacteria (LDB) is susceptible to growth. The Occupational Safety & Health Administration (OSHA) says that “Legionnaires’ disease is an infection of the lungs that is a form of pneumonia. A person can develop Legionnaires’ disease by inhaling water mist contaminated with LDB.” In order to prevent Legionella colonization in your water heater, and to prevent scalding from the water temperature being so high, we install a Thermostatic Control Valve on our Acrylic Walk In Bathtub line.
Another reason why we prefer to use the deck mounted Thermostatic Control Valve is because of the adjustable water temperature preset. The set point temperature of the TCV is installed at 104°F but once the bathtub is installed in your home, a bather can adjust the set point temperature to his or her own preference.
To learn how to clean a TCV click here. To learn how to change a TCV click here.
