Our house (built 1953) has galvanized piping for the cold and copper for the hot water supply lines. We had good water pressure (85 psi), but low flow (2.5 gpm).

I had a plumber replace the galvanized main water supply from the city water meter to the front spigot with 1.25 inch PEX. He also installed a PRV set wide open (80 psi).

At the front and back of the house, we are now getting 3 GPM. Unfortunately, when the outdoor hoses are on, the indoor water flow goes to a trickle.

The plumber says I should be able to get at least 6-11 GPM at the front spigot, but it is not happening. He assures me that the pipe from the water meter and our shutoff valve are clean. While I would love to get rid of the galvanized pipe under the house, it is not worth it until we can fix the flow to the front spigot.

Is there anything else that we can do? Is it possible there is something wrong with the city water supply, or the meter itself?

  • 2
    Galvanize pipe is at or past use before date. replacement now or very soon is a good idea. Did plumber test flow rate of the city pipes? Pressure is good but if low flow, then no go. City pipes might need replacing also.
    – crip659
    Aug 2, 2022 at 20:01
  • 2
    The corrosion growth in galvanized pipe is a real thing it will slowly drop everything to a trickle as it gets worse, I usually save a bad section for the home owner so they understand, also cutting some of the old out can dislodge chunks and slow down stream flow that may have happened.
    – Ed Beal
    Aug 2, 2022 at 20:10
  • 2
    I believe to troubleshoot this correctly you should start at your meter and measure the pressure/volume and then work your way, component by component, through the system until you find the restriction.
    – RetiredATC
    Aug 2, 2022 at 22:57
  • 1
    @crip659, the plumber did not test the city flow rate. I know of at least one neighbor on or street that has complained about water pressure in their house. Maybe I should contact the city.
    – Juan
    Aug 3, 2022 at 2:43
  • There are several possibilities but until you replace the line to the city main you may never get the flow you need, assuming the city can supply it. Even if the line is not completely failed we know it will.
    – Gil
    Aug 3, 2022 at 22:26


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