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Low water pressure

Tony MassiTony Massi Member Posts: 86
I'm trying to help out a friend. They bought an older home and in the sinks and shower when the hot and cold are used together the water pressure drops. The pressure coming into the house is 60 PSI and the water main is 3/4 or 5/8 ID the piping going to everything is 3/4 then down to 1/2 inch to the sinks etc. Would changing the piping from the water meter from 3/4 to 1 inch help. Some one suggested we change the pipe to 1 & 1/4 I think this is over kill.
Its a really bad pressure drop. There is no pressure reducing valve in the system. Also 3/4 in and out of the water heater.


  • JUGHNEJUGHNE Member Posts: 6,182
    Is the old piping iron or copper?
  • Tony MassiTony Massi Member Posts: 86
    Its all copper except when it runs up into the sinks and shower its that pex from the Home Depot . Also the shower body and faucets are new from the Depot.
  • JUGHNEJUGHNE Member Posts: 6,182
    Does the pressure on the main copper line, in the basement near the water meter, stay at about 60PSI when the shower, H & C is turned on? How small is the PEX?
  • JUGHNEJUGHNE Member Posts: 6,182
    Most likely 3/4" ips with even a lead goose neck at the main?
    He said older house, but it is all coppered up on the inside only.
    Would 3/4" copper "K" still be advised or 1" UG PEX?
  • Tony MassiTony Massi Member Posts: 86
    The house has copper coming from the street. Its in Suffolk County N.Y. and is aprox. 60 yrs old. The pex is 1/2 inch. I haven't tried to see if the pressure dropped when the H & C are on.
  • j a_2j a_2 Member Posts: 1,796
    Any possibility public works worker left the curb stop 1/2 are the neighbors pressures/volumes
  • hot_rodhot_rod Member Posts: 12,021
    Is there a pressure reducing valve on the main line somewhere. Could br defective or a plugged screen
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • Tony MassiTony Massi Member Posts: 86
    There is no pressure reducing valve.
  • JUGHNEJUGHNE Member Posts: 6,182
    There are a lot of devices between the water main and your shower:

    Corporation stop on the main...buried underground.

    Curb stop as mentioned above, should rotate a full 1/4 turn from on to off (the ones I know of). A partial closed really cuts things down.

    Your water service valve; If a gate type the gate may be not raising all the way. If a globe the washer could be hanging up.

    Water meter could have restriction.

    Back flow preventer at water meter could have issues.

    If any of these are problematic, you could have 60 PSI with no flow, but run some water the PSI falls on its butt.
  • Tony MassiTony Massi Member Posts: 86
    So your saying put a gauge on the system and run the water and if the pressure drops It could be restriction in the line or meter.
  • JUGHNEJUGHNE Member Posts: 6,182
    Depends upon where the gauge is placed. For instance put the gauge on the inlet of the water meter or any device. If water flow does not knock the pressure down severely at that point then the problem is not on the inlet side of that device but somewhere farther downstream. However if the pressure does a drastic fall there the problem is upstream of that point towards the main/supply.
    Did you check the neighbors pressure? If they had that problem it would be a much discussed item for all.

    I have found the curb stop problem and it made a world of difference in the house. It is good to exercise curb stops any time they are operated. If the house was winterized the curb stop was probably shut off. Just a fraction of the 90 degree turn can affect the flow. If you looked into one you would understand.
  • jonny88jonny88 Member Posts: 1,139
    You say you have pex.Did plumber run a homerun system or cut in tees whereever he wanted.Ever see the inside of a 1/2 inch pex fitting.Try putting a 5 gallon bucket under shower head see how long it takes to fill.Run other fixtures at the same time.If properly plumbed you should not have pressure drop.Remember pex is designed for home run system.This is a unscientific approach and I may stand corrected.Good luck and keep us informed.
  • j a_2j a_2 Member Posts: 1,796
    Yes I agree....he should be looking at a volume not pressure. Problem.....fixture values is what we size to how bout u new York guys...
  • j a_2j a_2 Member Posts: 1,796
    Youz guys seem to be pretty much in line with mass code....jerzy guys beat to a different drum...just kiddig lol
  • Tony MassiTony Massi Member Posts: 86
    I won't be able to check it out for a few days.
    I will get back with what I find.
  • Tony MassiTony Massi Member Posts: 86
    Put a gauge on the system got 60 PSI then ran some water in the sink and tub gauge dropped to 15 psi. Having the water company come and check out the curb stop. I'll get back with the results.
  • RobGRobG Member Posts: 1,850
    When the pubic works people show up you should be prepared to replace the main water valve inside your home. The gate probably broke when the PEX was installed.
  • jonny88jonny88 Member Posts: 1,139
    Don't you just love it when the old gate valves break shut(usually on a Friday night).AS long as you dont mind getting wet not a bad fix though.
  • JUGHNEJUGHNE Member Posts: 6,182
    Just to point out the small town rural advantage; we can call our utility at any hour and they will come out and locate the curb stop and shut off the water if need be.
    I always tried to record the location and depth of any curb stops I encountered on the electrical panel door or furnace door of that building. (measured out with tape measure from permanent structure, not 10 paces from tree etc). I have my own curb stop wrench that will fit/reach about 90% of what is around here.
    There are a few old water services with unknown stop locations.
    The utility also has recorded all stop locations as possible.
  • j a_2j a_2 Member Posts: 1,796
    That's nice of them to do that..up here the clock starts ticking and the towns get a min. 4 four hour fee. Shuting it down yourself although is easy but if it snaps the fee and fines are bad
  • j a_2j a_2 Member Posts: 1,796
    Price of water and sewer averages about 1k a year
  • JUGHNEJUGHNE Member Posts: 6,182
    Water & sewer here is about $385 a year, more if you have UG lawn sprinklers.
  • Tony MassiTony Massi Member Posts: 86
    Ok, Here's what happened. The water Authority came and removed the meter and tested the water pressure and the GPM before the meter. It tested at 60lbs pressure but only 3.3 GPM. They went out to the curb shut off and found it was not opened all the way. Then tested it again it had a GPM of 11.2 . They said 10.0 was acceptable.
    Problem solved.
  • j a_2j a_2 Member Posts: 1,796
    j a said:

    Any possibility public works worker left the curb stop 1/2 are the neighbors pressures/volumes

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