When I flush the toilets, turn on the washing machine or kitchen fawcet (cold water only) there is a quick groaning noise somewhere in the pipe system. I turned off the main intake valve, opened all the fawcets, etc. and drained the system and then recharged it; installed Sioux Chief water hammer arrestors on the washer, but no change. I then turned on every water fixture, inside and out, flushed the toilets several times and let the water run to get any air out of the pipes. The noise still persists. The only way I can reduce the noise is to close the main water supply valve about half way and also partially close the water valves leading to the toilets. There is not other way to regulate the water pressure, which I think might be the problem. I have city water, the house is 30 years old, and I never had this problem until the water company installed a new meter. Does any one know how I can fix this problem? Thank you! Paul

Problem is not water hammer. Therefore water hammer arrestors will have no effect. Problem sounds like a loose washer in a valve some where. Probably in the main shut off valve since partially closing it has an affect.

If you have a pressure reducing valve, it could be defective or could have trash in it.

There is no such thing as air in water supply pipes except in the extremely rare case where the pumping station or a well pump pumps air instead of water.

Harold:
Thank you very much for your reply. I have since found out that 2 pipes were rubbing against each other from the vibration when the water was turned on. I put some insulation between them. That stopped the noise temporarily, but now it has returned, but in another location I have yet to determine. If the pipes are rubbing against each other in the wall, there is no way I can get to them. Unless this would eventually cause damage to the pipes, I can live with the noise. Would installing a pressure reducing valve help?
Thanks again
Paul

You said that this began after the installation of a new water meter. If new meter was installed because city was increasing water pressure a PRV valve solve the problem.
Purchase a pressure gauge and see what your present water pressure is. If pressure is above 50-60 lbs. install a PRV.

Even though noise is coming from pipes vibrating against each each other or the house, what is causing vibration? I still suspect loose washer in main shut off valve.


https://www.askmehelpdesk.com/member...sure-gauge.jpg

Harold:
Thank you for the advise. The pressure is almost 80 PSI, so I believe a relief valve would help. I'll check the main shut off valve. The one before the water meter (the city's responsibility) shuts off completely, but the one after the meter (the homowner's responsibility) still leaks a little after it is shut off, so perhaps the washer/rubber "O" rings have to be replaced. Thanks again for all of your help - much appreciated!
Paul

Hello Derwiener,

I agree with Harold that you need to install a PRV see the image below.

What is considered normal water pressure? There really is no such thing as "normal" water pressure. Since water pressure is influenced by the elevation of the reservoir that serves your neighborhood versus the elevation of your water meter, water pressure varies from property to property. Water pressure in the District typically ranges from 45 - 125 psi; however, typical residential systems are designed to function best under a pressure of 40 - 60 psi. If the water pressure entering you home exceeds this level, you should install a pressure regulator in the line to reduce the pressure to an acceptable range. This protects your equipment and piping in your home from damage from excess force exerted by the water. Symptoms of high pressure include "clanging" or "rattling" of pipes that occur when a faucet, dishwasher, or washing machine shuts off; water heater pressure relief valve malfunctions, and reoccurring leaks. The symptom of low pressure is typically a noticeable reduction of flow, good luck

Thank you for the reply. I called a local plumber who also said that near 80 PSI for my house is way too high, and he will install a PRV next week. Hopefully that will resolve the problem. Thanks again.
Paul