Sometimes, shutting off the pump that distributes water to the affected area will eliminate the humming noise. If that's the case, the pump may have to be changed out for a different model or reset. In some instances, adding isolators and better stabilizing the pump works too (see rattling noises, below).
If your pipes sound like they're humming, it's likely a water pressure issue. When the water pressure is high, it can cause the water pipes to vibrate and create a humming sound. High water pressure is more common if you have a well for your water, but it can happen with municipal water as well.
Loose pipes can cause noisy vibrations, so make sure they're secured to wooden framing with pipe clips. If high water pressure is the issue, try adding a pressure-reducing valve. Homeowners can drain air chambers by turning off the water and opening the faucets and flushing the toilets.
Turn off the water supply to your house at the main supply (or street level). Open your faucets to drain all of the water from your plumbing system. Turn the water back on. The incoming water will flush the air out of the pipes but not out of the vertical air chamber, where the air supply has been restored.
After you turn off your mains water system and drain excess water from your residence, turning the water back on and running your faucets and house appliances that use water can remove air bubbles from the pipes.
While these sounds can be scary and seem like serious issues, the cause is usually quite benign. Most often, a loud sound coming from your pipes is caused by trapped air. By turning off your main water supply and running all faucets for 10-15 minutes, you force any trapped air through your water pipes.
Typically, banging noises coming from your pipes infer an issue with water flow or water pressure. Two of the most common causes are water hammers and trapped air bubbles. A water hammer, also known as hydraulic shock, occurs when fluid in motion is suddenly stopped when a faucet or valve is shut off.
More than just producing an annoying clamor, water hammer can actually damage the pipe connections and joints, resulting in water leaks and costly repairs. Worse, the noise may also indicate a larger problem, like excessive pressure in your water supply lines or loose piping.
Loose Fittings Causing Noisy Pipes
Pipework allows for the movement of water around your home, which means something is being carried through them, resulting in pressure and friction. If you hear clunking, rattling or vibrating from your pipes, it could simply be that your pipes aren't fitted correctly.
If your pressure is higher or lower, then you'll need to install, repair, or adjust your pressure regulator to comply. Adjusting your regulator is easy, as long as it's working properly. Simply tighten the screw down clockwise to increase pressure and counter-clockwise to decrease pressure.
High-pitched whistling from the plumbing is caused by excessive water pressure or flow speed. If your water pressure exceeds 60 psi, it's likely the pipes will give a high-pitched noise. The easy fix for high-pitched plumbing noises is lowering the water pressure to an appropriate level.
Spluttering taps, irregular flow and loud noises coming from your pipes can indicate the presence of air in your water lines. Air in water lines is not usually a serious problem for your plumbing system. However, if left unchecked, it can cause severe water-flow and noise issues in your home.
Air in water pipes also can have light sounds like hisses or small pops, so listen carefully. Now, sounds can come and go as regular use may help solve small pockets of air. However, if you hear these noises consistently, it is a sign that your plumbing system may need treatment.
Install a Water Hammer Arrestor: This device has an air-filled cylinder to absorb the impact of abrupt increases in water pressure. Most water hammer arrestors install between the shut-off valve and supply line via screw-type connectors.
Also called hydraulic shock, the signs of water hammer include a loud thumping or “hammering” noise from pipes carrying fluid and moderate- to heavy vibrations along the pipe system. Its impact can range from mild or undetectable vibrations to severe and very disruptive pressure shocks.
One method for eliminating water hammers is to create new air chambers that will serve as cushions for shockwaves. To do this, shut off your home's main water valve, then open the highest faucet in your home. Next, turn on the lowest faucet in your home and keep it on until all water has drained.
Usually happening about 30 seconds after the flush, the main cause of the noisy pipes when your toilet flushes is a faulty part in your fill valve. The fill valve is the part inside your toilet's tank that's responsible for bringing water into the tank.
Inspect for leaks: Check your water softener and its connections for any leaks, as these can introduce air into your water lines.
Air in hot water lines normally comes from your hot water tank. Trapped air will be released when you use the hot water in any faucet inside your house. That water pressure seems to be affected but remember that the real problem is coming from your water heater, not your water supply.
Flush ALL hot water taps for 15 minutes
Open ALL hot water sink fixtures, hot water bathtub or shower fixtures. Next, open all other hot water fixtures, such as in kitchens, wet bars, etc. Run all of these hot water fixtures for 15 minutes, then shut the water off.
If you've encountered these issues recently, you likely have air trapped in your water pipes. These air bubbles usually find their way to the highest points in your plumbing system, lower water pressure, and inhibit the flow of water through the pipes. Air in the water piping system can cause rust and corrosion.
An airlock in the pipes will eventually result in no water at all if it isn't taken care of. Even worse, it can cause blockages, overflows and other serious problems. Airlocks do sometimes fix themselves, but it isn't a risk worth taking.
How do you know if plumbing isn't vented properly? Signs of poorly-vented plumbing include gurgling sounds, slow drainage, bubbling water in the toilet bowl or empty toilets after flushing, or sewer smells.
Watch the Water Meter
Turn off all water faucets in your home and make sure the washing machine and dishwasher are not running. Check the water meter and make a note of the numbers you see. Come back in an hour and check again. If the numbers have changed, there's a leak somewhere.