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How to Test the Water Pressure in a House

Your city’s pumping stations control water pressure in supply mains. Mains pressure is set at 200 PSI (pounds per square inch) to supply elevated installations such as water towers and high-rise buildings. However, this kind of pressure would damage domestic plumbing and appliances.

Check your water pressure once a year.

Your city’s pumping stations control water pressure in supply mains.  Mains pressure is set at 200 PSI (pounds per square inch) to supply elevated installations such as water towers and high-rise buildings.

However, this kind of pressure would damage domestic plumbing and appliances.  Consequently, pressure is lowered to manageable levels by installing adjustable pressure reducing valves between the mains supply and household plumbing.

These valves are factory set at 50 PSI and are adjustable to a maximum of 75 PSI.  Pressure reducing valves can wear out, so household water pressure should be monitored periodically.

  1. Visit your nearest home improvement outlet and buy a domestic water pressure gauge.
  2. Turn off the water supply to everything that uses water in your household, such as water heaters, ice makers, sprinkler systems and washing machines. Make sure all faucets are shut off. This will allow you to measure accurately the static water pressure.
  3. Attach the pressure gauge to a threaded tap at floor level, such as a garden hose bib or a washing machine faucet.
  4. Turn the tap on slowly. Make a note of the static household water pressure when the gauge pointer stops moving. Turn the water heater, appliances and sprinkler systems back on. If the house water pressure is below 50 PSI or above 75 PSI, you may have a faulty pressure reducing valve. If it is within the stipulated range, but one or more of your faucets aren't producing enough flow, there is something causing the restriction.
  5. Call a plumber if the house water pressure is below 50 PSI or above 75 PSI, you may have a faulty pressure reducing valve. If the static pressure is within the stipulated range, but one or more of your faucets is not producing enough flow, something is causing the restriction. This could be a build–up of scale in one or more of the pipes in your household plumbing. If the house was built within the past 10 years, scale build-up is unlikely. On the other hand, if there is too much pressure at all the faucets, the pressure reducing valve is probably faulty. Consequently, only a professional experienced plumber would be qualified to trouble shoot the problem accurately.

Things You Will Need

  • Domestic water pressure gauge

About the Author

After graduating from the University of the Witwatersrand and qualifying as an aircraft engineer, Ian Kelly joined a Kitchen remodeling company and qualified as a Certified Kitchen Designer (CKD). Kelly then established an organization specializing in home improvement, including repair and maintenance of household appliances, garden equipment and lawn mowers.

Photo Credits

  • tap image by BlueMiniu from Fotolia.com
  • tap image by BlueMiniu from Fotolia.com