leak detectMost people consider high water pressure to be a good thing, and up to a certain point, it is. However, if it is too high, it can actually cause considerable and expensive damage to your home water distribution system.

Causes of high water pressure

One of the most common sources of high water pressure is the municipal water company. Getting water to multiple family dwellings, like apartment building, or high rise buildings. In addition, as more building development is done in an area, the demand for water increases, and water pressure is boosted to meet the higher demand. Water pressure in some neighborhoods can be as high as 100 pounds or higher. The maximum recommended water pressure for a residence is around 60 pounds.

Varying water pressure

Water pressure can also vary depending on the time of day. In the morning hours, when you and your neighbors are taking shower and getting ready for your daily activities, water pressure in your residence may go down because of a greater demand for the existing water supply in your neighborhood. However, during the day, when most people are not at home, or at night when most people are sleeping, the water pressure may increase due to a lack of demand.

Effects of high water pressure

Newer plumbing fixtures are designed to conserve water, they are designed to have a considerably lower rate of flow than older fixtures. High water pressure causes greater wear and tear on their internal parts, greatly reducing their life expectancy.   The same is true for the water piping, the higher the pressure, the greater the wear, especially on pipe joints.

Symptom of high water pressure

A common symptom of excessive water pressure in a home is recurring leaks in your water fixtures, such as faucets and shower valves. It could also cause intermittent leaks, like toilets running without being used, especially during hours of peak pressure, like at night when the pressure may be greater. High pressure can also cause “hammering or banging” noise from water piping inside the walls of your house when you turn off a faucet, shower valve or flush the toilet.

Water pressure reducing valves (PRV)

A water pressure reducing valve is a pressure regulator that reduces the water pressure coming from the main water line into the house. This valve brings down the pressure to a safe level before the water reaches any plumbing fixtures in the home.

water pipesHow water pressure reducing valves (PRV) work

A water pressure reducing valve is placed on the main water supply coming into the house before it actually enters the house. The PRV contains an adjustable spring loaded diaphragm which reduces the pressure of the water within the valve body. Water coming into the valve is constricted and then released at a reduced pressure. In addition to the spring loaded diaphragm, PRVs also contain a check valve. The check valve allows water to enter the house from the main supply, but prevents water from within the house to back flow and return into the municipal water supply during times of lower water pressure.   This helps the PRV deliver a more constant or steady water pressure and creates what is called a closed water supply system.

Closed water supply system

As stated above, a closed water system does not allow water from within a residence to reenter the municipal water supply. This is good, because it prevents possible contaminates from a residential water supply to back flow and enter the municipal supply. However, it also does not allow for water expansion caused by thermal expansion when water is heated by the water heater. Thermal expansion causes fluctuation in water pressure within the home water supply system and can cause problems for water heaters, water piping and fixtures in the home. Current building codes require the installation of expansion tanks for water heaters to compensate for thermal expansion. You could also have a closed system without the installation of a PRV, as many municipal water suppliers are installing back flow preventer in their supply lines before the water reaches your home. For a more detailed discussion of water heater expansion tanks, please see “Water Heater Expansion Tanks” on this web site.

We are at your service

If you think you may have high pressure problem, let us perform a test to determine exactly what is your water pressure. If your water pressure is excessive, we can install a PRV for you. If you already have a PRV, and still think your water pressure may be too high, let us check to see if the valve needs to be adjusted. PRVs are like any other mechanical device, they do not last forever, and your existing one may need to be repaired or replaced. Let Wood’s Plumbing be your full service plumber.