My neighbor came to me yesterday with a question: “Why does my kitchen faucet thump?” He was puzzled by the thumping or knocking sound that his faucet made every time he turned it on or off. I explained to him that this sound was not only irritating, but it could also signal a problem with his plumbing system that could cause leaks, damage, or poor water quality. I decided to write this article to share what I told him. I will tell you why your kitchen faucet thumps and what you can do to prevent it.
What Causes a Thumping Noise in Your Kitchen Faucet?
Water hammer, a phenomenon that causes a thumping noise in your kitchen faucet, is the most common cause. Water hammer occurs when the water flow in your pipes is suddenly stopped or changed by a valve. When this happens, the water that was moving at high speed creates a shock wave that travels back through the pipes and hits the walls, causing a thumping sound.
Water hammer can happen for several reasons, such as:
- High water pressure. If the water pressure in your home is too high, it can cause the water to flow faster and more forcefully through your pipes. This can make water hammer more likely and more severe when you turn off your faucet. You can check your water pressure by attaching a pressure gauge to an outdoor faucet and turning it on. The ideal water pressure for most homes is between 40 and 60 psi (pounds per square inch). If your water pressure is higher than that, you may need to install a pressure regulator or contact your water supplier to adjust it.
- Air in the pipes. If there is air trapped in your pipes, it can create bubbles that interfere with the smooth flow of water. When you turn off your faucet, these bubbles can collapse and create a shock wave that causes water hammer. Air can get into your pipes if they are new or if they have been repaired or replaced recently. Remove air by opening all the faucets at home and letting them run until no more air comes out.
- Sediment buildup. If there is sediment or debris accumulated in your pipes, it can create obstructions that reduce the diameter of the pipe and increase the water velocity. This can also make water hammer more likely and more severe when you turn off your faucet. Sediment can come from minerals in the water, corrosion of the pipes, or foreign objects that get into the plumbing system. You can flush out sediment from your pipes by opening all the faucets in your home and letting them run for several minutes.
How to Fix a Thumping Noise in Your Kitchen Faucet?
Depending on the cause of water hammer in your kitchen faucet, there are different ways to fix it. Here are some possible solutions:
- Install a water hammer arrestor. A water hammer arrestor is a device that absorbs the shock wave created by water hammer and prevents it from reaching the faucet and making noise. It consists of a small chamber filled with air or gas that acts as a cushion for the water. You can install a water hammer arrestor near the faucet or at any point along the pipe where water hammer occurs. You can buy a water hammer arrestor at any hardware store or online and follow the instructions to install it yourself or hire a plumber to do it for you.
- Replace the faucet valve. Water hammer can happen if your faucet valve is worn out or damaged. This is because the valve does not close properly or quickly enough when you turn off the faucet. This can allow some water to continue flowing through the pipe and create a shock wave when it hits the closed valve. You can replace the valve in your faucet by buying a new one that matches your faucet model and following the instructions to install it yourself or hire a plumber to do it for you.
- Insulate the pipes. If the pipes in your home are not insulated, they can vibrate and make noise when water hammer occurs. You can reduce this vibration and noise by wrapping insulation around the pipes or installing pipe clamps to secure them to the walls or floor. You can buy insulation or pipe clamps at any hardware store or online and follow
Is water hammer a problem?
Frequent water hammer can lead to severe harm to pumps, valves, and equipment as well as causing catastrophic failure of gasketed joints and expansion joints. The sound waves from the water hammer can also impact the integrity of pipe walls and welded joints. Additionally, water hammer can damage the fittings, connections, and joints, which can ultimately result in leaks.
Can pipes burst from water hammer?
Water hammer shockwaves can have detrimental effects, such as loosening or damaging pipes, taps, faucets, and appliances. In severe cases, the force from water hammer can cause pipes to rupture. If you hear rattling noises in conjunction with water hammer, it indicates that the pipes are becoming loose.
Do I need a plumber for water hammer?
Homeowners can typically get rid of water hammer inexpensively without the assistance of a professional.
The thumping noise in your kitchen faucet can be annoying and indicate a problem with your plumbing system. Water hammer causes this noise most commonly. This happens when a valve suddenly stops or changes the water flow in your pipes. High water pressure, the air in the pipes, or sediment buildup can cause water hammer. You can fix the water hammer by installing a water hammer arrestor, replacing the faucet valve, or insulating the pipes. By doing so, you can prevent water hammer from damaging your pipes and faucets. Enjoy a quiet and smooth water flow in your kitchen.
Read also: Why I Hear Noise When Running Hot Water?