Just bought a house. When using more than one anything in the house, the water pressure drops significantly. For exmaple: flush the toilet. While it's filling back up, the sink will just trickle water out. This is true for any 2 combinations of shower/faucet/toilet/washing machine in the house (basically anything that uses water). Doesn't even have to be in the same proximity to each other.

If using only one thing, the pressure is fine. I bought a pressure tester and hooked it up to the outside hose and it shows as 58, which from what I've read is normal.

This is a 2-story house if that matters.

Edit: Pictures

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3 Answers 3


I would look at your pressure regulator. The device between the meter and check valve. Since it sounds like your pressure is good it could be debris built up limiting the flow. I have worked on many homes with 1/2" plumbing and a toilet should not take a sink to a trickle in fact 2 sinks open should not affect each other as the orifices in the valves are much smaller so I would look to find what is limiting the flow and in my experiance this has been debris built up at restriction points.

  • House was built in 1992 - even a house that young would have build up?
    – mang
    Commented May 16, 2018 at 1:44
  • If you say so I am sure it is true I have worked on many different ages of homes but have not seen a home with copper have this problem including ones I still maintain and have since the 70' S that I have replaced the old galvanized with copper, the only problem I have found with hard water and possibly bad install of copper is pinholes causing leaks or dissimilar metals causing pipe failure,, but you obviously know better and don't have a clue.
    – Ed Beal
    Commented May 16, 2018 at 12:18
  • Sorry, I was just surprised. Wasn't trying to discredit your advise! Thank you for the help.
    – mang
    Commented May 16, 2018 at 14:01

Update: Pressure regulator was bad and needed replaced. As you can see, the nut was tightened as far as it could go. Plumber friend changed out the regulator and everything works fantastically!


Plumbing contractors have for years installed the homes plumbing with 1/2" copper or the equivalent size for any approved piping system. i/2" is large enough to supply only 1 appliance. When I built my home 20+ years ago I specified 3/4" plumbing on both the hot and cold supply lines and specified that only reducing tees could be used (no 1/2" tees anywhere). The plumber installed the cold line from the meter to the hot water tank in 3/4" and used 1/2" everywhere else. He had to return to correct his mistake. You need to check the size of the installed plumbing and if you want better delivery you may need to replace some of the piping. Check the piping size coming into the home and all that which is installed. Report back with your findings and someone will be able to make some recommendations or give you some ideas. Also, check to see if you have a filter system in your home that needs replaced.

  • Added pictures to the original post of my water meter. Appears to be 3/4" by the label?
    – mang
    Commented May 15, 2018 at 14:07
  • If the house is old and never had a water softener. Lime buildup inside the pipe can reduce flow. Commented May 15, 2018 at 15:40
  • House was built in 1992
    – mang
    Commented May 16, 2018 at 1:40

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