The mixing valve of a shower is installed in order to mix cold water with hot water from the water heater installed in your home before sending the water through your pipes to your shower. Installing a mixer valve is done primarily to prevent scalding accidents from occurring when using the shower. The mixer valve is placed right in the shower where it monitors the temperature of the hot water and mixes in cold water to achieve a target temperature.
Adjust the temperature of the shower by turning the flow tap on fully. The flow tap will only dispense hot water. Wait one to two minutes for the water to reach maximum temperature.
Turn on the temperature tap to add cold water to the hot water from the flow tap. Press down on the tap knob, depressing it into the mixer housing from its resting position to adjust the temperature of the water.
Adjust the flow of the cold water until a desired temperature is reached. Most mixer valves come with a maximum preset temperature for safety reasons. This maximum temperature will limit the flow of hot water through the valve. To increase this maximum temperature, unlock the valve by pressing the valve safety button on the end of the valve knob and increasing the flow of the hot water through the mixer.
Lock the mixer valve into place. To lock most valves, release the valve so that it rises back into resting position. Turning on the shower will now use the newly mixed temperature.
When setting the temperature be careful not to choose a setting that may lead to scalding after extended exposure.