Thermostatic shower mixer is a safety device that you install to prevent yourself and your family from scalding or freezing while in the shower. It provides a flow of a preset constant temperature even if the water pressure from cold or hot water drops, the thermostatic shower mixer will automatically adjust the water flow to compensate from the low supply of either cold or hot water.
Aside from adjusting the flow of hot and cold water to ensures that the water temperature does not vary by more than 1 to 2 degree's C , there is an automatic shut down in case the hot or cold water supply fails. There is a temperature control dial either numbered or high to low temperature dial for easy temperature selection and adjustable maximum temperature setting which if you desire hotter water temperature, there is a button that you have to press simultaneously turning the dial to prevent from accidentally turning up too high temperature, this also serve as a child protect button too. There are thermostatic mixers for showers only but also there are that has diverter to switch between bath filler or shower head.
To work well, for a walk in shower that is fed by an indirect water system, the cold water storage tank should be at least 3 ft above the shower head. If the performance is poor, you can increase the pressure by installing a pump or either raising the storage tank, while to get the best performance out of your thermostatic shower mixer, both hot and cold water pressure needs to be balance. Majority of the mixer showers can be installed on main fed system, high pressure systems (combination of boiler or unvented cylinder) or from a tank fed system, low pressure systems which use cylinder and cold water storage tank. For a high pressure system, it recommended to install a pressure balancing valve to eliminate the temperature fluctuations while for a low pressure system a shower pump can be added to the installation since the thermostatic shower mixer does not increase or decrease the pressure of the water.Aside from the safety and convenient features, the different brands and models of thermostatic shower mixer has different designs, materials, finished and shower head which can fit any design of your bathroom. Depending on the brand and model you choose, a complete thermostatic shower mixer cost around $300 to $4,000, some brand includes the installation fee already. Before buying and installing one, check if the specific thermostatic shower mixer is compatible to the type of water pressure since some cannot cope with a huge difference in water pressure from both temperatures and it has a maximum capability of degree of temperature input. If the budget allows a thermostatic shower mixer is a great feature added in your bathroom.