Mixer Showers: Not Just a Coed Party Game!

Mixer showers are so called because they will mix the existing hot and cold water, in a special valve, before it is available at the shower head. This type of shower runs from your domestic hot water system and is the cheaper option. The drawback with this type of shower is that it may be difficult to control the shower temperature and if you have a combination boiler, may require extra fittings during installation.
They are suitable for either low or high pressure (check with your supplier that the mixer valve you buy is suitable for the system you have). They are available as surface mounted fixtures, where the pipe work is easily installed on the top of your existing surface, or flush mounted, where the valve is seen, but the pipe work is hidden behind the surface. They are then ideal to install in a new shower cubicle construction where the pipes can be built into a wall.
To operate correctly both the hot and the cold water need to come from a source operating at the same pressure. Both can come from a main feed system, (combi boiler or multi point water heater and cold mains) or both can come from tank fed water (immersion and cold storage tank). If one supply must come from high pressure and one from low pressure, a pressure balanced mixer valve can be installed.
A mixer shower will not increase the flow of water to your system. If your water flows from your taps at a poor rate, this is the rate it will feed the shower.
A drawback to installing a mixer shower is the fact that it will usually be connected to pipes which supply water to other points. When the other points are used (taps, toilet cistern etc) the flow rate to the shower will be affected. This in turn will affect the temperature of the water coming out of the shower and, in the case of the cold being drawn off elsewhere, could lead to scalding. This can be overcome, with a low pressure system, by laying separate pipes to the valve from both hot and cold supplies and making the shower water independent. You may need to contact a plumber for this as it will mean installing a special flange in the top of your hot water cylinder. In the case of a mains fed mixer a thermostatic valve is recommended. Mixer showers cannot be pumped from a mains pressure system (combination boilers, multi point heaters) but they can from low pressure systems.
There are mixer shower valves especially designed for combination boilers, (pressure balanced mixer shower).
Advantages - Cheaper to buy/install
Disadvantages - Water temperature can be affected by other water using items in the home

Cryste Wisne has been in the California Custom Shower Business for the past 10 years. She has used her vast experience as a Contractor , design, installation, and implementation of custom showers in California.