A mixer shower takes cold water and hot water from your heating system and mixes them together to achieve the desired temperature. Most shower mixer valves require the hot and cold water supplies to be of equal pressure.
Mixer valves can be divided into two distinct styles, surface mounted and recessed.
Surface mounted valves can be used in almost any situation, as the pipework is mounted directly onto the wall. Surface mixer vales normally come with a slider rail kit and shower hose to enable the shower height to be adjusted to suit the user. Some can also be used with fixed pipework, popular in traditional designs, with a fixed head shower rose
Recessed mixer valves can be used when the walls are hollow, such as plasterboard partition walls or if there is a space behind the wall to conceal the body of the valve, such as an airing cupboard. Recessed shower mixer valves enable most of the pipework to be hidden, which gives a much neater finish. Recessed valves normally come with a fixed shower head although some are available with slider rail kits.
Manual or Thermostatic Shower Mixer
Thermostatic mixer showers have a special device built into them that regulates the water temperature to within a degree or two of that selected, and are generally more expensive than manual mixer valves.
Manual shower mixer valves do not maintain a constant temperature if the flow of water to the shower is altered (for example if someone turns on a kitchen tap while the shower is in use). This can result in the shower water temperature rising sharply or, more commonly, falling sharply. This must be taken into consideration if the shower is to be used by children, the elderly or disabled. The water supply to a manual shower can be altered to overcome this problem, but thermostatic showers are now relatively cheap, so it is easier to opt for one of these.