What Is Water Hammer And Why Does My Plumbing Bang?

If you hear loud banging, thumping, or knocking sounds when water shuts off, you may be experiencing a plumbing problem known as water hammer.

Water hammer is one of the most common causes of pipe noise in residential plumbing systems and can lead to increased wear on fixtures, valves, water heaters, and plumbing components.

Hot Water Pros provides water heater and plumbing diagnostics throughout Indianapolis and surrounding communities.

What Is Water Hammer?

Water hammer occurs when moving water suddenly stops or changes direction.

The momentum of the water creates a pressure shockwave that travels through the plumbing system.

This pressure wave can produce:

- Loud banging noises

- Knocking sounds

- Vibrating pipes

- Shaking plumbing fixtures

Many homeowners first notice water hammer when a washing machine, dishwasher, toilet, or faucet shuts off quickly.

What Causes Water Hammer?

Several issues may contribute to water hammer.

Common causes include:

- High water pressure

- Failed expansion tanks

- Missing hammer arrestors

- Fast-closing valves

- Loose plumbing pipes

- Pressure fluctuations

A professional inspection can determine the exact cause.

High Water Pressure

One of the most common causes of water hammer is excessive water pressure.

High pressure can:

- Stress plumbing components

- Increase pipe movement

- Damage fixtures

- Trigger relief valve discharge

Many homes operate at pressures higher than recommended.

Failed Expansion Tanks

Expansion tanks help absorb pressure changes created when water heats inside the plumbing system.

When an expansion tank fails, homeowners may notice:

- Water hammer

- Relief valve dripping

- Pressure fluctuations

- Plumbing noise

Expansion tank issues are often overlooked.

Loose Plumbing Pipes

In some homes, plumbing pipes are not properly secured.

When pressure changes occur, the pipes may move and strike framing members.

This often creates:

- Banging sounds

- Knocking noises

- Vibrations

Proper support can help reduce movement.

Can Water Hammer Damage My Plumbing?

Yes.

Repeated pressure shocks may contribute to:

- Pipe wear

- Fixture damage

- Valve failures

- Water heater stress

- Leak development

The sooner the problem is corrected, the better.

How Can Water Hammer Be Fixed?

The solution depends on the cause.

Common repairs include:

### Water Pressure Testing

Pressure testing helps identify excessive system pressure.

### Pressure Reducing Valve Replacement

A failing PRV may contribute to pressure fluctuations.

### Expansion Tank Replacement

A properly functioning expansion tank helps absorb pressure spikes.

### Hammer Arrestor Installation

In some situations, hammer arrestors may help reduce pressure shock.

Current Pricing

### Pressure Reducing Valves

- Existing PRV Replacement – $389 Installed

- New PRV Installation – $429 Installed

### Expansion Tank Replacement

- Expansion Tank Replacement – Starting at $499 Installed

### Water Heater Replacement

- 40 Gallon Electric Water Heater – $1,599 Installed

- 50 Gallon Electric Water Heater – $1,599 Installed

- 40 Gallon Gas Water Heater – $1,849 Installed

- 50 Gallon Gas Water Heater – $1,849 Installed

- Tankless Water Heater Replacement – Starting at $4,299 Installed

Why Indianapolis Homeowners Choose Hot Water Pros

Hot Water Pros specializes in water heater and plumbing diagnostics.

We provide:

- Water pressure testing

- PRV replacement

- Expansion tank replacement

- Water heater repair

- Water heater replacement

- Upfront pricing

We proudly serve Indianapolis, Carmel, Fishers, Westfield, Noblesville, Greenwood, Brownsburg, Whitestown, and Zionsville.

Need Help With Banging Pipes?

If your plumbing system is making loud banging or knocking sounds, Hot Water Pros can identify the cause and recommend the most cost-effective solution.

Call 317-922-9043 today to schedule service.