Call a plumber: banging all over the house

Why this happens

Oatey lists high water pressure, loose pipes and quick-closing valves among the usual causes of banging pipes, and says pressure above 80 psi can make pipes vibrate and bang. EPA WaterSense says most US plumbing codes require a pressure regulator where supplied pressure is over 80 psi, and that high pressure can damage pipes, fixtures and appliances and raise the risk of leaks. The city utility in Lakeville, Minnesota says that if you hear banging pipes, it is possible a pressure reducing valve has malfunctioned. Sioux Chief says repeated shock waves can damage a pressure reducing valve.

What to do right now

1. If you smell gas at any time, leave the house and call 911 and your gas utility from outside. The Pennsylvania PUC says not to turn lights on or off or make calls from inside.
2. Make a quick map for the plumber: which fixtures bang, hot or cold, and how loud.
3. If you can, check the pressure. This Old House says to turn off all water-using appliances and fixtures first, and its expert Richard Trethewey recommends an inexpensive gauge on a hose bib. EPA describes attaching a pressure gauge to a hose bibb, to the cold-water faucet for the washing machine hookup, or to a cold-water faucet on the first floor, then opening that faucet fully. Keep the faucet closed while you attach the gauge and set a towel under it. This Old House says to look for an outdoor faucet or hose bib, and that is the simplest choice. Using the washing machine faucet means closing it and taking the hose off, so have a towel and bucket ready and keep water away from the washer's plug and outlet. If water reaches them, stay out of the water and do not touch the plug, because Ready.gov says not to touch electrical equipment if it is wet or if you are standing in water. Write down the reading and where you took it, then close the faucet and remove the gauge.
4. Do not adjust, remove or replace a pressure regulator yourself. Give the reading to the plumber.
5. Call a licensed plumber to check the pressure and the regulator and to say where shock arresters belong. EPA says a pressure regulator creates a closed system and to check local plumbing codes on whether thermal expansion needs to be addressed, so ask the plumber about it.
6. You can also ask your water utility about the pressure at your service. EPA says to confirm with the public water supplier that service pressure does not exceed 80 psi.

When to stop. If you see a leak, a damp wall or a stain, shut off the main water valve by hand and call a plumber now. Never force a stuck valve.

Start this troubleshooter over

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