What Everyone Should Know About Water Heaters and Water Pressure

Household plumbing fixtures are made to operate with a maximum pressure of 80 psi, but the pressure coming from the municipal water supply is commonly 100 psi or more. This is why the pressure reducing valve (commonly called a PRV) is so important. The PRV works by using a pre-tensioned spring to apply pressure to a disk, and as the high pressure from your water supply flows through this valve the disk counters high pressure with the pressure from the spring. This only allows a certain amount of water into your home to control the pressure inside. When a PRV fails there is usually a noticeable difference in water pressure throughout the home. Another source of increased pressure inside your home comes from the heating of water inside of your water heater.


As water is heated it expands and because water can't be compressed that extra volume has to go somewhere or else it can cause big problems with your heater or elsewhere in the home. Over time, too much pressure can cause any number of problems. The common problems are: the pressure release valve on the side of the water heater may start slowly leaking water and the exhaust flue on a gas powered water heater may malfunction.

o As an example on how water expands when it is heated, when the water in a 40 gallon water heater is heated from 90 degrees to 140 degrees it expands by nearly one-half gallon.

In order to protect your water heater and the rest of the plumbing in your home it is important to install a thermal expansion tank that is connected close to your water heater.

o Thermal expansion tanks work by having a bladder inside of them that is pressurized with air. As water is heated and expands it pushes on this bladder causing it to compress and make room for the extra volume. This is likely the solution that you should look at if your water heater's pressure release valve is leaking.

If you notice higher than normal pressure at your faucets, outside faucets, tub, or shower you should have your water pressure checked to make sure that your PRV hasn't gone bad. It is much easier to check early and replace a PRV than to worry about having to replace parts in your toilets, tub and shower valves, and faucets due to damage from high water pressure.




By R Scott Roberts
Article Source: http://EzineArticles.com/8559905