Low water pressure in house all of a sudden

Low water pressure in house all of a sudden. That may be triggered by a glitch in the water supply system if you suddenly have no water pressure in the whole building, maybe a broken water main many blocks away, or by your pressure regulator.

You’ll need a pressure meter that screws onto a laundry or outdoor faucet to test the regulator.

On a faucet, screw the meter, open the faucet all the way, and check the pressure.

Open the pressure regulator, normally located in the basement or outside of the water meter, by turning the nut counterclockwise with a wrench for around a quarter turn.

It should raise the pressure slightly, but not by much. The pressure regulator needs to be replaced if it leaps more than 20 psi.

If no matter how much you turn the nut, the pressure does not change at all, the issue is on the supply side. When you finish this test, be sure to return the nut to its original location.

Low water pressure in house all of a suddenLow Water Pressure In House All Of A Sudden

To detect the very base of the problem, it is important to know how it originated. Following are the reasons responsible for low water pressure:

  • The issue may not be connected to your plumbing system. Municipal water lines are often prone to clogs, erosion, leaks, and other malfunctions that can affect the water pressure, much like residential plumbing.
  • The valve on the water meter can also be tested. It could be that the valve was partially locked by a utility worker, in which case you’ll have to arrange for the city to open it back up again.
  • While you’re at it, search the key shut-off valve. The main shut-off valve, which opens and closes the supply of water to your house, is normally located near the water heater inside or near the water meter outside.

Private water service linePrivate Water Service Line

  • A large leak in your private water service line that branches off the public water service line can cause a drop in water pressure that affects all plumbing fixtures in your house.
  • Shut off all the taps inside and outside to see if you have a leak and take note of the water meter.


  • Pipes will not last forever. They’ll grow leaks as rusty, galvanized steel pipes wear out.
  • Your plumbing is corroded by some very clear red flags, like rust-colored water or water with noticeable metallic flakes.
  • If, when using hot water, you just feel a pressure drop, chances are good that the issue is with your water heater.
  • The possible cause is the pinching of scale buildup off the supply line of hot water.

Scale buildup will slow down water to a trickle on plumbing fixtures. Using white vinegar, limescale may be stripped from fixtures, although this is just a temporary repair.

There are many causes of having low pressure suddenly but it’s better to cross-check all the fixable things before making a firm decision.

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