What to Do When Your Water Heater Starts Making Noise

Your water heater is one of the hardest-working appliances in your home. When it begins making unusual sounds—whether popping, banging, rumbling, hissing, or crackling—it is signaling a problem. While many homeowners ignore these noises until the heater stops working, addressing them early can prevent leaks, energy waste, and full system failure.

This guide explains the common causes of water heater noise, how to troubleshoot, and when to contact a professional like Shamrock Plumbing for safe repairs.

Common Water Heater Noises and What They Mean

1. Popping or Crackling Sounds

This is the most common complaint and is usually caused by sediment buildup at the bottom of the tank. Mineral deposits settle over time, trapping water beneath them. When the water heats up, it pushes through the sediment and creates popping sounds.

Why it matters:Sediment causes overheating, reduces efficiency, and shortens the life of your water heater.

2. Rumbling Noises

Rumbling occurs when hot water forces its way through layers of hardened sediment. This indicates a more advanced stage of buildup.

Potential risks:

• Tank overheating

• Higher utility bills

• Risk of tank failure

3. Hissing Sounds

If you hear hissing, especially from an electric water heater, it may mean the heating elements are in contact with sediment or excessive scale.

Other possibilities:

• Water leaking onto a hot surface

• Pressure inside the tank becoming unstable

4. Sizzling or Spitting

These noises often point to a water leak dripping onto the burner in gas water heaters or onto heating components in electric models.

This requires immediate repair, as leaks can lead to tank corrosion or complete system damage.

5. Banging or Hammering

If the noise occurs when water stops flowing abruptly, it could be water hammer, caused by sudden pressure changes in your plumbing system.

Water hammer can damage pipes and fittings over time.

What You Can Do Before Calling a Plumber

While some issues require professional service, homeowners can take a few basic troubleshooting steps.

1. Check the Temperature Setting

If your water heater is set too high (above 120°F), it may cause excessive pressure and noise.

Adjust it and listen for changes.

2. Flush the Tank

Flushing removes sediment and can eliminate popping or rumbling noises.However, if your heater has never been cleaned or is more than 8–10 years old, flushing may not be enough and could even cause leaks due to weakened tank walls.

In that case, call Shamrock Plumbing for a safe assessment.

3. Inspect for Visible Leaks

Look around the base and connections:

• Are there drips near the valves?

• Is water pooling under the tank?

• Do you see corrosion or rust?

Any sign of leakage should be handled by a professional.

4. Check the Pressure Relief Valve

If the valve is releasing steam or water, the system may be experiencing excessive pressure.

Never try to repair this yourself.

When to Call Shamrock Plumbing

Your water heater should run quietly. If the noises persist after basic troubleshooting—or if you notice any of the following—call for service immediately:

• Water is discolored or rusty

• Hot water runs out quickly

• You hear loud banging or metallic sounds

• Water heater is older than 10–12 years

• Rumbling continues after flushing

• You see leaks or dripping

Shamrock Plumbing provides trusted water heater diagnostics, repairs, flushes, replacements, and safety evaluations to keep your home running efficiently.

How Shamrock Plumbing Can Help

Our licensed plumbers use professional tools such as:

• Sediment flushing systems

• Pressure testing equipment

• Tank inspections

• Heating element checks

• Valve safety assessments

Whether your heater needs cleaning, repair, or full replacement, we provide long-lasting, energy-efficient solutions.

Keep Your Water Heater Running Quietly and Efficiently

Ignoring unusual noises can lead to bigger issues, higher bills, or even tank failure. Regular maintenance and early intervention can add years to your water heater’s lifespan.

Shamrock Plumbing is here to help homeowners stay safe, comfortable, and informed with expert water heater services and preventive care.