What to Do When Your Water Heater Is Making Noises

Listen Carefully to Identify the Type of Noise

The first step is to listen carefully to the type of noise your water heater is making. This can help you diagnose the potential problem. Some common water heater noises include:

  • Rumbling or gurgling sounds – This usually indicates sediment buildup in the tank. Flushing the water heater can help clear out the sediment.
  • Knocking, banging or popping noises – This points to expansion and contraction of metal components as the tank heats and cools. If loud, it likely means a loose part hitting the side of the tank.
  • Hissing or whistling – This suggests a leak somewhere in the water heater letting air escape. Leaks need to be identified and fixed.
  • Screeching or grinding – These worrisome noises indicate an internal part of the water heater is failing, like a bad burner, valve, or motor. Professional service is needed.

Paying attention to when the noise is occurring, if it’s constant or intermittent, and correlating it with your hot water usage can also provide clues as to the problem.

Inspect the Water Heater Exterior

After listening to the noise, conduct a visual inspection of the outside of the water heater. Look for:

  • Dents, cracks, or corrosion on the tank – Signs of damage or rupture.
  • Leaking or rust around fittings or pipes – Indicates a leak is present.
  • Loose cables, valves, burner components – May be rattling around and causing noises.
  • Unusual readings on temperature/pressure gauges – Could mean settings are off.
  • Smoke or unusual smells – Points to problems with the burner.

Any external issues identified should be addressed. Leaks need immediate fixing before major damage occurs.

Check That the Water Heater Is Level

If you hear banging or knocking noises, check that the water heater is properly leveled. Being slightly tilted can make components shift and vibrate as water is heated and circulated. Use a spirit level to ensure the tank is plumb. Adding shims under the base can help level it if needed.

Drain and Flush the Water Heater Tank

Certain noises like gurgling point to sediment accumulation in the tank. Draining and flushing the tank helps remove built-up silt, limescale, and rust. Turn off power to the heater. Attach a garden hose to the tank drain valve and route it to a safe drainage area. Open the valve and drain completely. Open inlet valve to refill and flush out a few times. This routine maintenance can quiet rumbling noises.

Examine Internal Components

For persistent or severe noises, the inner parts of the water heater may need examination. Hire a professional to inspect the following:

  • Burner – Check for obstructions or debris causing whistling or grinding. Ensure gas flame is blue.
  • Heat flue – Remove blockages which can lead to rumbling sounds.
  • Anode rod – If rattling, may need replacement to prevent tank corrosion.
  • Expansion tank – If damaged, could cause knocking noises from water pressure.
  • Sediment – Heavy buildup can dislodge and rumble during heating.

Repair or replace any damaged internal components. A plumber or appliance repair technician can help with this.

Adjust the Water Temperature Setting

If noises persist after inspecting and cleaning, adjust the temperature setting on the heater. Excessively high temps can lead to louder expansion and contraction of pipes. Lower to around 120°F. This may reduce banging or ticking sounds during heating cycles.

Replace the Water Heater If Necessary

For older heaters that have reached their lifespan, noises like grinding or screeching may indicate irreparable failure requiring replacement. Leaks, tank corrosion, or dangerous combustible issues also necessitate a new unit. When problematic noises can’t be resolved, replacement by a water heater installation pro is the best solution.

When to Call a Professional

Seeking professional assistance is recommended if:

  • Noises indicate a dangerous combustible issue with the gas burner.
  • You have leaks, ruptures, or serious tank damage.
  • Noises persist after troubleshooting and tank flushing.
  • Internal components are faulty and need replacement.

A technician can properly diagnose the noise cause and make needed repairs or install a new water heater if required. Don’t delay in addressing strange water heater noises to prevent major damage.

FAQs About Noisy Water Heaters

What causes water heaters to make noise?

Common causes include sediment buildup in the tank, loose internal components, leaks, expansion and contraction of pipes and metal parts, improper water temperature settings, and failing components like the burner or flue.

What kind of noises should I be concerned about?

Grinding, screeching, and loud banging or popping noises are particularly worrisome, as they may indicate component failure requiring repair. Hissing can mean a leak.

Can I troubleshoot noises myself?

Doing external inspections and tank flushing are good DIY first steps. But for persistent noises or those indicating component failure, hire a professional for service. Internal repairs require expertise.

How can I prevent noises in the future?

Flush the tank annually to remove sediment. Keep the temperature at a moderate 120°F. Install an expansion tank to allow for pipe expansion. Replace older units nearing their lifespan.

When should I replace instead of repairing a noisy heater?

If internal components like the burner or heat flue are failing and causing noises, replacement is usually better than sinking money into an old, inefficient unit with ongoing issues.


Strange gurgling, banging, hissing or rumbling coming from your water heater should never be ignored. These noises usually signify an underlying issue that needs troubleshooting and fixing. Listen carefully to diagnose the problem. Visually inspect the exterior, check that the heater is level, and drain the tank to remove sediment. For persistent noises, have a professional inspect the inner components like the heat flue, burner, and anode rod. Adjusting the temperature setting lower may also help reduce noises in some cases. If you have an older unit where costly repairs are needed, replacement is often the best solution for reliable hot water delivery. Addressing odd water heater noises ASAP can help prevent leaks, damage, safety issues and breakdowns. With some preventative maintenance and prompt troubleshooting, your water heater can go back to operating quietly and efficiently.