Having a washing machine that causes water hammer can be both noisy and potentially damaging to your plumbing system. Water hammer, also known as hydraulic shock, occurs when the flow of water is suddenly stopped or changed direction, creating a loud banging noise and pressure surges within the pipes. This issue is common in households where the water pressure is high or the plumbing system lacks proper shock absorption. Fortunately, fixing water hammer associated with your washing machine is often straightforward and can be achieved with some simple troubleshooting steps. In this guide, we will walk you through the causes of washing machine water hammer and provide effective solutions to eliminate the noise and protect your plumbing.
How to Fix Washing Machine Water Hammer
Identify the Cause of Water Hammer
Before attempting to fix the water hammer, it’s important to understand what’s causing it. Common causes include:
- High water pressure in your home’s plumbing system
- Rapid closing of the washing machine’s water inlet valves
- Loose or poorly secured pipes that vibrate during water flow
- Absence or failure of water shock arrestors or cushions
To diagnose the problem, listen carefully during washing machine operation. The banging noise typically occurs when the washer fills, drains, or stops mid-cycle. If the noise is loud and persistent, it indicates a need for intervention.
Check and Adjust Water Pressure
Excessively high water pressure can significantly contribute to water hammer. To check your home’s water pressure:
- Obtain a water pressure gauge, which is inexpensive and available at hardware stores.
- Attach the gauge to an outdoor faucet or laundry tub faucet.
- Turn on the water fully and read the pressure. Normal household water pressure is typically between 40 and 60 psi.
If your pressure exceeds 60 psi, consider installing a pressure-reducing valve (PRV). To adjust or install a PRV:
- Shut off the main water supply.
- Detach the existing PRV or install a new one inline with your main water line.
- Adjust the valve to reduce pressure to a safe level (around 50 psi).
- Turn the water back on and verify the pressure reading.
Reducing water pressure helps minimize the force of water hitting pipes suddenly, reducing water hammer.
Install or Replace Water Shock Arrestors
One of the most effective solutions for water hammer caused by washing machines is installing water shock arrestors, also known as water hammer arrestors or cushions. These devices absorb the sudden pressure changes and prevent noise and pipe damage. To install or replace shock arrestors:
- Locate the washing machine’s water inlet hoses and valves.
- Turn off the water supply and disconnect the hoses.
- Install the shock arrestors inline with the inlet hoses or directly onto the valves, following manufacturer instructions.
- Ensure all connections are secure and leak-free.
- Turn the water back on and run the washing machine to test for noise reduction.
If your current shock arrestors are old, damaged, or missing, replacing them is a simple yet effective fix.
Secure and Support Loose Pipes
Loose or unsupported pipes can vibrate excessively during water flow, amplifying water hammer sounds. To remedy this:
- Inspect the pipes near the washing machine and throughout the laundry area.
- Use pipe clamps or brackets to secure loose pipes to the wall or framing.
- Ensure pipes are properly supported and not sagging or rubbing against other objects.
- If necessary, add padding or insulation around pipes to dampen vibrations.
Properly secured pipes reduce movement and noise caused by hydraulic shocks.
Adjust or Replace Washing Machine Inlet Valves
The washing machine’s inlet valves can cause water hammer if they shut too quickly or close with force. To address this:
- Inspect the inlet valves for signs of damage or malfunction.
- If the valves close abruptly, consider installing slow-closing or pressure-assisted valves.
- Replace faulty valves with new ones designed to close gently.
- Ensure the inlet hoses are not kinked or obstructed, which can cause pressure surges.
This adjustment helps to reduce the sudden stoppage of water flow, decreasing water hammer noise.
Reduce Water Velocity and Flow Rate
In some cases, restricting water flow can help mitigate water hammer. You can do this by:
- Installing flow restrictors or adjustable valves on the inlet hoses.
- Ensuring that the washing machine’s water inlet filter is clean and unobstructed.
- Adjusting the wash cycle settings to slower fill modes, if available.
Reducing flow velocity can lessen the impact when water is suddenly stopped, minimizing hydraulic shock.
Regular Maintenance and Inspection
Preventative measures are vital for avoiding water hammer in the future. Regularly check your plumbing system for:
- Loose or vibrating pipes
- Damaged or worn inlet valves
- Clogged filters or screens
- Proper installation of shock arrestors
Addressing small issues promptly can prevent loud noises and costly damage over time.
Summary: Key Points to Fix Washing Machine Water Hammer
Water hammer caused by your washing machine can be effectively addressed through a combination of troubleshooting steps and preventive measures. Start by checking your home’s water pressure and installing a pressure-reducing valve if necessary. Installing or replacing water shock arrestors is often the most straightforward solution to absorb hydraulic shocks. Securing loose pipes and ensuring inlet valves close gently can significantly reduce noise. Regular maintenance and inspection help keep the plumbing system in optimal condition. By implementing these strategies, you can enjoy quieter laundry cycles and safeguard your plumbing infrastructure from damage caused by hydraulic shocks.
