A water pressure regulator is generally connected to the water line running from a utility company's water supply into your home. This device is bell-shaped, and regulates the amount of water pressure that is sent into your housee. When a water pressure regulator begins to make moaning or groaning noises, it can be a sign of a problem.
Low Water Pressure
The water pressure regulator is preset by the manufacturer to control the amount of water pressure sent into the home. The common water pressure setting is between 45 and 60 pounds-per-square-inch (PSI). When the water pressure falls below the minimum setting, the water pressure regulator may make a moaning noise to signify that it's below-level.
High Water Pressure
High water pressure develops when the water pressure regulators quits controlling the amount of water pressure the pipes receive. A common problem called "water hammer" develops when the water pressure is excessively high. In this case, when the faucet is turned on, a high flow of water shoots out of the faucet. Turning off the faucet when the water pressure is high causes the "water hammer," where water bounces back into the system while making a moaning or groaning noise. Other noises can also develop when water hammer occurs.
Most water pressure regulators have a reduction valve that helps regulate the water pressure running into the home. The valve can malfunction or become damaged, restricting the flow of water into the pipes. Restricted water flow can cause the water pressure regulator to make a moaning noise which can be heard through the water pipes.
A water pressure regulator can become clogged with debris that gets into the main water supply or city water pipes. The clog will restrict the water flow being sent into the pressure regulator. Once water flow is restricted, the water pressure regulator will attempt to send the proper amount of pressure through the water pipes running into the home. A moaning sound can be heard when the water pressure regulator is attempting to send water pressure into the home, but cannot because of a clog in the system.