Whistling water pipes accompany various plumbing problems. Tracking the noise to its source may take time, but finding and dealing with the cause can reduce wear and tear on plumbing fixtures and appliances.
When water pressure is too high, it can cause pipes to vibrate, producing high- or low-pitched sounds. The International and Uniform Plumbing Codes Handbook suggests pressures of 18.1 to 22.7 Kilogram per square inch (psi) for residential properties.
Loose or damaged washers---particularly those in faucets and toilet valves---can create whistling or other noises as water rushes past them.
Water pipes conduct sound readily, so whistling and other plumbing noises can occur far from their source.
Keep home water pressure at or below 60 psi, and replace the water pressure regulator if pressures creep higher. If whistling occurs when a sink runs or while a toilet refills, replace faucet washers or toilet flush and refill valve washers.
According to The International and Uniform Plumbing Codes Handbook, plumbing fixtures are generally designed to tolerate pressures of no more than 80 psi. High water pressure in the home strains supply lines, valves and appliances and increases the risk of rupture and associated water damage.