We have low water pressure in our house (we are on city water).

Wendy C
by Wendy C
The city came out and tested the water pressure at the street access (their responsibility) and of course said it was not considered low by their standards. The outside hose bibs are slow - can't run two at one time (back yard & front yard), and our kitchen faucet is PAINFULLY slow. We've taken apart the faucet and checked for a diverter (not the issue), checked that all water controls are completely open, but nothing helps. Sometimes our dishwasher will not run because it senses a "block" in the incoming water line (not consistent - we think that may be related to water pressure too). We've had the suggestion to 1) drain our water heater; 2) get a "pump" to attach at the main line into the house to push water through; and lots of other strange ideas. Any suggestions?
  7 answers
  • Hudson Designs Hudson Designs on Aug 04, 2011
    Hello Wendy, What was the pressure at the city side? Their side I would expect to be around 100 PSI. Your line pressure should be around 50-80 PSI. Over time a build up of scale in side older copper and metal pipes can cause the flow to slow down. This maybe your problem. You can get a pressure gauge and attach it to the hose bib to see the pressure there. Understand that Pressure and rate of flow are two different things. If you house is older you may think about having the service from the street replaced.

  • Hudson has some very valid points here. Pressure and volume are different things. Even if you have pressure if the pipe delivery size is small, then your not going to get the volume out of the pipe. Ideal piping systems would have at least a 1 inch main coming into the house. 1 inch or 3/4 inch main pipes going to the hot water heater, and at least through the basement in which the pipes running to the fixtures tap into it. New construction uses 3/4 inch pretty much all the way to each fixture in the house. The older homes used 1/2 inch to the outside fixtures a lot. Nowadays 3/4 inch pipe is used. There are a few ways to get around this issue. Re-pipe all visible pipes in basement to larger size, or install a booster pump with storage tank. Both methods have their benefits and draw backs. In a local town near me, the street pressure is fine, but the volume of water is not. almost everyone has booster pumps in their system. Piping in the basement can be difficult to do, but with the invention of Shark Bites and or Pex tubing, you can do the entire job without doing any soldering at all. Installing a pump system is not out of the reach of many do it your self types but it is more involved and really should be done by a professional plumber. Pumps can be installed to service the entire home, or just your outside pipes.

  • Wendy, Excellent comments from Hudson & Woodbridge, especially the discussion on pressure vs volume. We could run the full gamut of advice but think it is best if we had more information first. A few questions... When was your house built? Are you on a crawlspace or a slab? Any of your immediate neighbors have similar problems or is it isolated to your house? How long has it been a problem? Is it getting worse? Tim

  • KMS Woodworks KMS Woodworks on Aug 05, 2011
    I'd be curious to know the numbers as well....they city said pressure is good...but did they provide a number. And how did they determine this? most main are buried deep under the street and there "measurement point my be blocks away

  • Paul M Paul M on Aug 05, 2011
    If you do what Hudson is saying and your pressure is good but your flow is not the you have build up in your pipes. If you don't know how to check your pressure you can get one of these and find out. http://www.amazon.com/Rain-Bird-P2A-Water-Pressure/dp/B00004RACK If your pressure is normal and your flow is still slow increasing your pressure won't help and it may damage some of your fixtures. If your pipes have build up in them I don't know what you could do besides replace them. Hopefully that is not the issue.

  • French Remodeling French Remodeling on Aug 05, 2011
    If you have galvanized pipe in your house or as an entrance line then that is probably the problem. If you have a copper entrance line and copper plumbing in the house I would check the pressure regulater or backflow preventer.

  • Ellen C Ellen C on Aug 11, 2011
    Speaking of backflow preventer...that had crossed my mind as a potential culprit. There is a possibility that the valve has an issue. Also, if there is a master valve shut-off at the house (look in the crawl or garage), it may not be open fully. Also be sure that the valve at the meter is fully open. If water was ever turned off at the house for plumbing work or due to a vacant property, it's possible that the those may not be fully open....much easier to check the simple stuff first.