Reasons for Water Pressure Drop

A drop in water pressure, whether sudden or gradual, can make everyday life miserable. Unscrupulous plumbers will sometimes charge a homeowner for unnecessary repairs. Before it happens to you, take the time to become familiar with common reasons for a drop in household water pressure. This knowledge will ultimately save you money and unnecessary inconvenience.

Before trying anything else, conduct a quick inspection of the water shut-off valves for your house. All valves should be in the full, open position. Most valve handles in the open position run parallel with the pipe. A valve in an angled or cross-position relative to the pipe will restrict water flow.

Most homes have a main shut-off valve inside the house or garage. Check near the water meter for the other valve location. If the low pressure is confined to one plumbing fixture, check the shut-off valve for that fixture to ensure it's open fully.

A gradual decrease in water pressure might indicate a mineral buildup in showerheads or faucet aerators that slows the water. If you notice a crusty off-white mineral buildup, try simple cleaning methods. Remove the showerhead or aerator and remove the mineral deposits with a toothbrush dipped in white vinegar or products similar to CLR designed to remove calcium. If minor cleaning doesn't remedy the water pressure drop, the problem could be extensive mineral or rust buildup in old galvanized pipes within the house.

If everything appears normal in the first two areas, it may indicate a problem with the main water line. The section of pipe leading from your house to the street could be damaged or obstructed. Homes in new neighborhoods can suffer unintentional water line damage from construction materials and equipment. Invading tree roots can block or damage water lines in older, established neighborhoods.

One of the worst-case scenarios deals with an interior pipe leak causing, at some point, a drop in water pressure and damage to the structure. A read of your water meter will confirm a hidden leak. Begin by turning off all interior and exterior water taps then taking an initial water meter reading before leaving for work in the morning. Upon return, check the meter again. If the usage has increased, there is a good possibility your home has a hidden leak.

While not common, the water meter could be to blame for water pressure fluctuations. It is very unlikely the water meter will cause a drop in water pressure unless significant blockage exists within the unit itself. If you have checked every other option and suspect a water meter problem, call your water provider. They will perform a bypass test to detect internal obstructions or a malfunction.

If you have a well water system, your issues could be related to parts of the well. The well pump could be the culprit if it's getting old, becomes clogged, or breaks. Other possible well issues that can make pressure drop include a bad pressure tank, failing pressure switch, or a bad well. Have your well inspected if you suspect the issues are coming from the well itself and not the plumbing inside your home.