Plumbing Advisors Editorial TeamEditorial StandardsReviewed July 19, 2026Source-CheckedThe short answer
What this problem usually points to
Popping or rumbling can come from sediment and boiling pockets, while clicking, buzzing, hissing, or banging can involve normal expansion or a component that needs testing. Stop the unit and arrange service if the noise is loud, new, paired with a leak, or accompanied by a burning or gas odor.
Schedule plumbing service soon
The problem may become more disruptive or damaging if it continues, so arrange an inspection instead of repeatedly working around it.
What the visible pattern can mean
These are routing clues, not a confirmed diagnosis. The safe next step changes with where the water appears, which fixtures are affected, and whether the problem is active.
| What you notice | What it may mean | Safe next step |
|---|---|---|
| The tank pops or rumbles while heating | Sediment may be trapping water at the bottom of the tank | Note when the noise occurs and arrange maintenance or diagnosis |
| A tankless unit clicks or hums unusually | Flow, scale, fan, ignition, or another component may need testing | Record any display code and leave the cover closed |
| Noise comes with leaking, steam, or odor | Pressure, overheating, combustion, or electrical risk may be present | Keep away and request urgent service |
Safe checks and important limits
Safe checks you can make
- Note the sound and whether it occurs at startup, during heating, or after a faucet closes.
- Check for visible water or a display code without touching the unit.
- Compare whether the sound comes from the heater or nearby pipes.
Stop before these steps
- Do not open burner or electrical panels.
- Do not drain a hot tank or alter the relief valve to test the noise.
When to call a plumber
- Call for a new, loud, or worsening noise or reduced hot-water performance.
- Stop and get prompt help for steam, a leak, gas odor, burning smell, or repeated breaker trip.
Recommended services
Where to start
Start with the first service below. A plumber can confirm whether a related service is needed after inspecting the problem.
Questions homeowners ask
Frequently asked questions
Is the water heater is making an unusual noise an emergency?
Schedule plumbing service soon. The problem may become more disruptive or damaging if it continues, so arrange an inspection instead of repeatedly working around it.
What can I check safely before a plumber arrives?
Note the sound and whether it occurs at startup, during heating, or after a faucet closes. Check for visible water or a display code without touching the unit. Stop if the situation changes or the check would require opening a wall, drain, appliance, or powered component.
Which plumbing service should I request?
Water Heater Repair is the best starting point for this visible symptom. A plumbing professional still needs to inspect the system before confirming the cause or repair.
What should I tell the plumber?
Share when the problem started, whether it is constant or intermittent, which fixtures are affected, and any water, odor, noise, temperature change, or recent plumbing work you noticed.
Sources and further reading
These references support the safety and system guidance used to route this observable plumbing problem. They do not diagnose a specific property.
