Vent, Valve & Volt
Low water pressure at one faucet or the whole house

You can fix this

Likely cause: a main shutoff that is not fully open

A main shutoff left partly closed after work cuts pressure to the whole house. Open it fully.

Why this happens

Mr. Rooter lists partly closed shutoff valves as a cause of low water pressure and says to make sure both main shutoffs, one at the meter and one at the home, are fully open. Home Depot says the main shutoff is usually where the water pipe enters the house, on the same side as the meter.

How to fix it

  1. Find the main shutoff where the water pipe enters the house, usually on the same side as the meter.
  2. Gate valve (round wheel): turn it counterclockwise until it stops to open fully. Ball valve (lever): open when the handle lines up with the pipe.
  3. Check the valve on the meter side the same way if you can reach it.
  4. Run a faucet and compare the flow.

When to stop. If a shutoff will not turn, do not force it. Berkeys advises calling a plumber for a seized valve.

If this does not fix it, tell the plumber

  • Whole-house pressure is low, and whether a main shutoff was recently closed.
  • Whether opening the shutoffs fully helped.
  • Whether any shutoff is stiff or seized.

Build the full list: what to tell the plumber.

Start this troubleshooter over

References (every fact above comes from one of these pages)
  1. Mr. Rooter: What causes low water pressure?
  2. Home Depot: How to turn off the water to your house
  3. Berkeys: Is it a mistake to think the plumber will handle all the prep?

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