Does the water pressure and/or the temperature of the water change when somebody is taking a shower and somebody else flushes a toilet or turns on a dishwasher?. The reason could be one or more of the following:

  • Pressure-Balancing Mixing Valve vs a Thermostatic Mixing Valve.
  • The shower head.
  • The bathroom piping is restricted and or undersized.

Mixing ValvesPressure Balanced Valves are those ones which have a single handle for the shower control, they generally sense changes in hot or cold water pressure (such as a toilet being flushed or a cold water tap being turned on) and compensate the temperature fluctuation by reducing the hot or cold water pressure to provide a constant temperature. The water pressure or flow at the shower head will reduce. You can see examples on Home Depots website.

Thermostatic Mixing Valves – Can change the flow or volume of water without changing the temperature. There are Thermostatic Mixing Valves which can be installed at the top of hot water tanks for the whole house and ones which have two handles which can be placed inside individual showers.

The thermostatic mixing valve for your hot water tank can be set to a higher temperature to help control bacterial contamination such as (Legionnaires’ disease) meanwhile the temperature at the shower head is at a lower temperature. You can see examples on Home Depots website or you can look at the pictures to the right.

You can purchase a thermostatic mixing valve for an individual fixture such as a shower or sink or you can purchase a whole house valve which connects at the top of the hot water tank. The thermostatic mixing valves are more expensive then a pressure balancing valve and in all cases a licensed plumber should be consulted to identify the right valve for your situation.

Shower Heads – If you have low water pressure at your shower head it may be caused by the shower head or the bathroom plumbing. You can try to clean the shower head or you can purchase a high pressure shower head. A high pressure shower head is designed to deliver higher water pressure with the same amount of water flow.

This is achieved through either adjustable spray settings or a pressure chamber design. Adjustable spray settings simply condense your shower head spray for a smaller but stronger shower. A pressure chamber works by adding air and pressure to the shower water, forcing the water out at higher pressure.Bathroom Piping Restricted/Undersized.

Plumbing Distribution Pipes Restricted or Undersized – If you generally have low water pressure in your house, which can be more common in older areas of the city, it may be caused by the Municipalities water supply and or the piping in your house such as the diameter of the pipe or type of pipe such as Galvanized Piping. You should consult with a licensed plumber to review your options.

Traditional Shower Handle - Both Pressure and Temp
Thermostatic Mixing Valve - Pressure and Temp separated
Thermostatic Mixing Valve - Single Unit
Thermostatic Mixing Valve - Top of Water Tank
Thermostatic Mixing Valve Unit - For Hot Water Tank