Why Do My Pipes Bang When I Turn On the Tap? Understanding Water Hammer

When you turn on the tap, and your pipes respond with a sudden, jarring bang, it’s more than just a plumbing quirk. That sound is likely caused by water hammer, a plumbing issue that’s as serious as it is loud.

Many homeowners in Toronto and the surrounding areas deal with noisy pipes that start off as an occasional nuisance but can quickly lead to real damage if ignored. In this blog, we’ll walk through what water hammer is, what causes it, and what you can do about it.

What’s Behind the Bang? The Causes and Clues of Water Hammer in Your Pipes

Water hammer occurs when the flow of water inside your plumbing system suddenly stops or changes direction. This abrupt shift creates a shockwave that slams through your pipes, often causing that infamous pipe banging sound.

This shock is usually triggered by:

• Appliances that shut off water quickly, like washing machines or dishwashers
• High water pressure that forces water through too quickly
• Loose pipes that vibrate when the pressure shifts
• Valves that are old, faulty, or not closing properly
• Missing or waterlogged air chambers that would normally absorb the pressure surge

Here’s how you know you might have a water hammer problem:

• Loud banging noises immediately after turning off a tap or appliance
• Shaking or vibrating pipes inside walls or under floors
• Leaks or moisture around joints, baseboards, or ceilings

These symptoms are warning signs that your plumbing system is under stress.

The Role of High Water Pressure

High water pressure increases the likelihood and severity of water hammer. When water rushes through your pipes at excessive pressure, any sudden shut-off causes a more violent stop, amplifying the shock.

Residential systems should not exceed 80 PSI. Ideally, your household water pressure should fall between 40 and 60 PSI. You can test this with a pressure gauge that attaches to an outdoor faucet. If it’s too high, installing a pressure regulator can help bring things back into a safe range.

How Air Chambers Help Prevent Water Hammer

Air chambers are vertical sections of pipe filled with air, installed near faucets or valves. They act like shock absorbers, cushioning the water flow when it stops suddenly. Over time, though, these chambers can become filled with water, making them ineffective.

Some newer homes use mechanical water hammer arrestors, which offer a more durable and compact solution. Whether your home uses traditional air chambers or arrestors, it’s important to maintain or replace them when they stop doing their job.

Diagnosing the Problem: When to Call a Plumber

You don’t always need to call a plumber the first time your pipes bang, but consistent pipe noise should never be brushed off. Start with a quick DIY assessment:

• Test your water pressure
• Watch for patterns (specific times, appliances, or fixtures)
• Secure any visible loose pipes

But if any of these situations apply, it’s time to call in a professional:

• Repeated loud banging after using appliances or fixtures
• Visible leaks or water stains on walls or ceilings
• Water pressure consistently above 80 PSI
• Unusual drop in water pressure or inconsistent flow

A licensed plumber can identify hidden causes and recommend permanent fixes that go beyond surface symptoms.

Solutions for Water Hammer and Noisy Pipes

Here are some common solutions and whether they’re DIY-appropriate or better left to the pros:

The right fix depends on what’s causing the issue and how your plumbing is configured. A quick fix may offer relief, but a long-term solution will protect your plumbing for years to come.

Why Ignoring Water Hammer Can Lead to Bigger Plumbing Problems

Water hammer isn’t just an annoying sound; it’s a red flag that your plumbing system could be heading toward costly damage. Over time, the repeated pressure surges can cause pipe joints to separate or even break entirely.

Leaks may develop as a result, leading to mould growth, structural weakening, and water staining throughout your home. High-pressure water surges can also take a toll on your appliances, reducing their lifespan or damaging sensitive components.

In more extreme cases, persistent water hammer can crack or burst pipes altogether, causing sudden and severe flooding. And even if the damage isn’t visible yet, the wasted water from these issues often results in higher utility bills. What may seem like an occasional knock now can spiral into emergency repairs and unexpected costs if left unresolved.

Stop the Bang: Get Water Hammer Fixed by the Experts at Brothers Plumbing

If your pipes are banging and rattling, it’s time to take the noise seriously. Water hammer is a signal that something deeper is happening within your plumbing system. At Brothers Plumbing, we’ve been helping Toronto homeowners get to the root of noisy pipes and water pressure issues for decades. We’ll assess your system, explain what’s going on, and recommend solutions that make sense for your home.

Whether it’s installing a pressure regulator, securing loose pipes, or resolving a long-standing water hammer issue, we’ve seen it all. We offer full-service plumbing for everything from drain cleaning to fixture installation and emergency repairs, backed by a team of licensed, experienced professionals.

If you’re hearing the telltale signs of water hammer, let’s fix it before it leads to bigger problems. Reach out to Brothers Plumbing today at 647-247-2230 or click here to get in touch online.

FAQ: Water Hammer and Noisy Pipes

What is water hammer in plumbing?
It’s a pressure surge that happens when water flow is abruptly stopped or redirected, causing a loud banging in your pipes.

Can water hammer damage my pipes?
Yes. Over time, repeated surges can weaken joints, cause leaks, and damage plumbing fixtures.

Is water hammer dangerous?
It’s not harmful to people, but it can seriously impact your plumbing system and lead to costly damage.

How do I stop water hammer in my house?
You can reduce your water pressure, install arrestors, or have a plumber assess and upgrade older plumbing components.

Should I call a plumber for noisy pipes?
If the banging is frequent or growing louder, it’s wise to have a plumber inspect the system before further damage occurs.