How to stop water hammer

Imagine enjoying a peaceful evening at home when suddenly, you hear a loud bang or a series of banging noises coming from your pipes. This phenomenon, known as a water hammer, can be alarming and disruptive. Not only does it create an unpleasant noise, but it can also cause damage to your plumbing system over time.

Here we will delve into the world of water hammer and provide practical tips and solutions to stop it. So, let's explore how you can maintain a tranquil and fully functioning plumbing system in your Australian home.

Understanding Water Hammer

A water hammer refers to the loud banging or knocking sound that occurs when the flow of water is suddenly interrupted or changes direction. It usually happens when a valve is closed abruptly, causing a surge of pressure through the pipes.

This rapid increase in pressure creates a shock wave, resulting in a distinct banging noise. A water hammer is most commonly experienced in hot water systems and can be a persistent issue in many Australian households.

The Consequences of Water Hammer

While a water hammer may initially seem minor, its long-term consequences can be significant. The repetitive banging can cause pipes to weaken, joints to loosen, and fittings to wear out over time.

If left unchecked, this can lead to leaks, burst pipes, or even structural damage to your home. Therefore, taking proactive measures and learning how to stop water hammer to protect your plumbing system is crucial.

What Causes Water Hammer?

A water hammer is caused by a sudden change in water flow or direction within a plumbing system, resulting in a rapid increase in pressure. Several factors can play a role in the occurrence of water hammers. Here are some common causes:

Quick-closing valves

Valves that close rapidly, such as those found in washing machines, dishwashers, or even faucets, can create a water hammer. When the valve shuts off abruptly, it stops the water flow, causing a surge of pressure through the pipes.

Water pressure surges

High water pressure can increase the likelihood of a water hammer. If the water pressure in your plumbing system exceeds the recommended limit (typically 80 psi or pounds per square inch), it can put excess strain on the pipes. Any sudden change in water flow can result in a pressure surge and subsequent water hammer.

Air chambers

Air chambers act as cushions to absorb the shock waves caused by the water hammer. Over time, however, air chambers can become filled with water, losing their effectiveness. Without the air cushion, the pressure surge from sudden water flow changes cannot be adequately absorbed, leading to a water hammer.

Long pipe runs

Long pipe runs can contribute to the occurrence of a water hammer in larger buildings or homes with complex plumbing systems. The length of the pipes provides more opportunity for water to gain momentum, increasing the force of the pressure surge when the flow is suddenly stopped or changed.

Improper pipe sizing

Incorrectly sized pipes can contribute to a water hammer. If the pipe diameter is too small, the velocity of the water flow can increase, making it more susceptible to pressure surges and a water hammer. Proper pipe sizing ensures a balanced flow and minimises the occurrence of water hammers.

Water supply line issue

Issues with the main water supply line, such as the sudden opening or closing of water metres or the operation of pumps, can cause water hammer. These events can create rapid changes in water flow and subsequent pressure surges.

Common Signs of Water Hammer

Signs of a water hammer can manifest in various ways. Here are some common signs to look out for:

Banging or knocking noises

The most noticeable sign of a water hammer is the loud banging or knocking noise coming from your pipes. These noises typically occur when you shut off a faucet, turn off an appliance that uses water (like a dishwasher or washing machine), or when a valve closes abruptly. The noise is caused by the sudden change in water flow and the resulting pressure surge.

Vibrations or rattling sounds

A water hammer can cause vibrations or rattling throughout your plumbing system. You may feel the pipes vibrating or hear a rattling sound when the water flow changes abruptly. These vibrations occur due to the pressure wave travelling through the pipes.

Movement of pipes

It could be a sign of a water hammer if you notice visible movement or shaking of your pipes when you turn off a faucet or shut down a water-using appliance. The sudden pressure surge can cause pipes to shift or shake.

Leaks or damage

Over time, a water hammer can cause damage to your plumbing system. It can weaken pipes, joints, and fittings, leading to leaks or burst pipes. If you notice any unexplained leaks or damage to your plumbing, it's important to investigate if the water hammer is the underlying cause.

Water pressure fluctuations

A water hammer can sometimes result in fluctuations in water pressure throughout your home. When the phenomenon occurs, you may experience momentary surges or drops in water pressure.

It's worth noting that not all signs may be present in every instance of water hammer. However, if you notice any combination of these signs occurring repeatedly, it's a good indication that you are dealing with a water hammer in your plumbing system.

Effective Measures to Stop Water Hammer

Adjust your water pressure

High water pressure is a common cause of a water hammer. Excessive pressure can strain the pipes, making them more susceptible to shock waves. Check your water pressure using a pressure gauge available at most hardware stores.

If the pressure exceeds 80 psi (pounds per square inch), consider installing a pressure-reducing valve or regulator to maintain safe and steady water pressure.

Secure all loose pipes

Loose or inadequately secured pipes can exacerbate water hammer. Inspect your plumbing system and ensure all pipes are securely fastened with clamps or straps. This will minimise vibrations and movement, reducing the likelihood of water hammer occurrence.

Installing water hammer arresters

Water hammer arresters are designed to absorb the shock waves caused by sudden water pressure changes. These devices act as cushions, preventing the pressure surge from reaching the rest of the plumbing system.

Installing water hammer arresters at strategic points, such as near appliances or valves, can eliminate water hammers. Consult a professional plumber to determine the appropriate type and size of water hammer arresters for your specific needs.

Adding air chambers

Air chambers are another effective solution for stopping water hammer. These vertical pipes, typically installed near fixtures or appliances, contain air that acts as a cushion to absorb pressure surges.

Over time, air chambers can become filled with water, reducing their effectiveness. To remedy this, turn off the water supply, open the affected faucet or valve, and allow the air chamber to refill with air. Repeat this process periodically to ensure optimal performance.

Regular maintenance

Prevention is always better than cure. Schedule regular maintenance checks for your water system to identify and address likely issues before they escalate. A professional plumber can inspect your pipes, valves, and appliances, ensuring they are in good working order and free from obstructions or leaks.

Preventive Measures to Avoid Water Hammer

In addition to the steps mentioned earlier for stopping water hammer, here are some preventive measures you can take to minimise the chances of water hammer occurring in the first place:

Slow-closing valves

Consider replacing quick-closing valves with slow-closing ones. These valves gradually reduce water flow, minimising the abrupt pressure surge that causes water hammer.

Water pressure regulators

Install a water pressure regulator at the point where the main water supply enters your home. This device helps maintain consistent and safe water pressure, reducing the risk of water hammer.

Proper pipe sizing

Ensuring your plumbing system is properly sized and designed can help prevent water hammer. Adequate pipe diameter, layout, and support will reduce the likelihood of pressure surges and subsequent water hammer occurrences.

Water flow control devices

Certain appliances, like washing machines and dishwashers, can have flow control devices or solenoid valves equipped that gradually reduce water flow when shut off. These devices can help minimise the occurrence of water hammers.

Get Expert Help to Stop Water Hammer

Water hammer can be a frustrating and potentially damaging issue within your plumbing system. Understanding its causes and taking the preventive measures above are crucial to addressing a water hammer.

However, it's important to recognise that every plumbing system is unique, and some situations may require expert assistance. If you've tried the suggested solutions and the water hammer persists, or if you're unsure about tackling the issue yourself, it's advisable to seek the help of an expert plumber.

They have the knowledge and expertise to assess your specific plumbing system, identify underlying problems, and provide tailored solutions to stop a water hammer.