What is a Water Hammer and How Do You Fix It?

You're washing the dishes when suddenly—BANG!—a loud thumping noise echoes through your pipes, making you jump. That startling sound is called water hammer, and while it might sound like your plumbing is about to explode, it's actually a common plumbing issue that many homeowners face.

What Exactly is Water Hammer?

Water hammer (also known as hydraulic shock) is that loud banging or thumping noise that happens when water flowing through your pipes suddenly stops or changes direction. Think of it like a car slamming on its brakes—the water keeps moving forward with momentum, then hits a wall when a valve closes, creating a shock wave that travels back through your plumbing system.

This phenomenon isn't just annoying—it can actually damage your pipes, joints, and fixtures over time if left unchecked.

What Causes That Banging Sound?

Several common culprits can trigger water hammer in your home:

• Fast-closing valves - Appliances like washing machines and dishwashers have solenoid valves that snap shut quickly
• High water pressure - Excessive pressure (above 60 psi) makes the shock waves more powerful
• Loose pipes - Pipes that aren't properly secured can bang against walls and framing
• Faulty air chambers - These shock absorbers in your plumbing can get waterlogged over time

Simple DIY Fixes You Can Try

Before calling a plumber, try these homeowner-friendly solutions:

1. Drain Your Air Chambers

Your plumbing system has built-in shock absorbers called air chambers. To recharge them:

• Turn off your main water supply valve
• Open all your faucets to drain the system completely
• Close all faucets and turn the water back on

This lets air refill the chambers so they can absorb shocks again.

2. Secure Loose Pipes

Check areas where pipes run through walls, floors, or ceilings. If you can access them, add pipe straps or cushioning to prevent movement. Even simple foam pipe insulation can help reduce banging.

3. Install Water Hammer Arrestors

These are small devices you can install near problem appliances. They work like mini shock absorbers and are relatively easy to add to washing machine connections or other quick-closing valves.

When to Call a Professional

If the simple fixes don't work, or if you notice:

• Persistent banging that's getting worse
• Signs of water pressure problems throughout your home
• You can't access the pipes causing the issue

It's time to call a licensed plumber. They can check your water pressure, install pressure-reducing valves if needed, and properly secure any hard-to-reach pipes.

Final Takeaway

Water hammer might sound scary, but it's usually fixable with some basic DIY maintenance. Start with draining your air chambers and securing loose pipes—these simple steps often solve the problem. If the banging continues, don't ignore it. Persistent water hammer can lead to costly plumbing damage down the track, so it's worth getting it sorted properly.