Why Do My Plumbing Pipes Make A Knocking Noise?
November 10, 2018 Plumbing
We've all heard strange noises around our homes and most of the sounds are harmless. But if you hear banging water pipes, this could be a sign of a serious plumbing problem. The top three causes of banging plumbing pipes are because of a water hammer, copper pipes or too high of water pressure. These sounds can be heard after a water supply is shut off, while the water is running and randomly throughout the day or night. Here are more in-depth reasons why your plumbing pipes are banging and remedies for those noises.
When running water and is suddenly shut off, the rushing water has no place to go and slams against the shut-off valve. The sound you hear is called a water hammer. It may not sound like a big deal but a water hammer can potentially damage joints and connections in the pipes.
To address the water hammering, you'll need to inspect all visible piping while the noise is present to see if there are any loose or vibrating parts that need securing. Next, you'll need to check the air chamber. The air chamber is the vertical pipe located near your faucet and is often in the wall cavity that holds the plumbing connected to your sink or tub. The purpose of the chamber is to absorb the shock of fast-moving water that is suddenly stopped. Unfortunately, over time it loses its effectiveness and it will need to be replenished. To do that, turn off the water supply to your house. Open the faucets to drain out any water. Then turn the water supply back on. The incoming water will flush the air out of the pipes but not out of the air chamber. The air supply will then be restored to your air chamber.
You may also hear banging sounds coming from your plumbing if your home has copper pipes. Copper pipes tend to expand as hot water passes through them. If these pipes are in a tight area, they will expand and noisily rub against other structural features.
In most cases, expanding and contracting copper pipes will not cause a leak. And unless you are remodeling, there's no reason to add additional padding around these pipes. The simple solution would be to slightly lower the water temperature setting on your hot water heater.
Another reason for banging water pipes is that the water pressure is too high. Most modern homes have pressure regulators that mount where the water supply enters the house. You may consider having one installed if your home doesn't have one. Too much water pressure could damage any water-supplied appliances like your washing machine or dishwasher. It's recommended that water is delivered to your home at no lower than 40 and no greater than 80 psi (pounds per square inch).