Tankless Water Heater Repair & Installation in Kennesaw, GA

A tankless water heater makes some noise during normal operation: a fan spinning up, a click as the igniter fires, a soft whoosh from the burner. When those sounds change, or new ones appear, they are often the earliest sign of a problem. For Kennesaw homeowners, learning which noises are normal and which are not can turn a vague worry into a useful description for the technician. If yours is a tank model, see our water heater overview for Georgia instead.

Normal sounds from a tankless unit

When a hot tap opens, the unit senses flow, the fan starts to purge the combustion chamber, the igniter clicks or sparks, and the burner lights. You may hear the fan change speed as the burner modulates, and a short run-on after the tap closes as the fan clears remaining exhaust. Electric units hum or click as relays switch the elements. These sounds are steady and repeat the same way each time.

Sounds that call for attention

• Repeated clicking without lighting: the igniter tries but the burner does not prove flame, so the gas supply, the igniter and the flame sensor are all suspects.
• Rumbling, crackling or kettle-like boiling: often scale in the heat exchanger creating hot spots where water flashes to steam.
• A loud, rattling or grinding fan: worn bearings, debris in the fan housing or a loose cover.
• Whistling or a high-pitched whine: water or gas forced through a restriction, such as a partly closed valve or clogged inlet screen.
• A bang when the burner lights: delayed ignition, which needs prompt attention.
• Banging pipes when taps close: water hammer in the plumbing, not the heater itself.

Why delayed ignition is not a wait-and-see noise

A pop or bang at ignition means gas built up briefly before lighting. Causes include a weak igniter, a dirty burner, incorrect gas pressure or a vent problem. Repeated delayed ignition can stress the heat exchanger and the vent connections. Turn the heater off at its gas valve and power supply, and schedule service. With any smell of gas, get out of the house and phone the gas utility or 911 from a safe distance.

Scale noise and what fixes it

Kettle-like sounds that build gradually over months usually point to scale. A descaling service, with solution circulated through the heat exchanger by way of the service valves, typically quiets it and restores lost output. If the unit has no service valves, adding them simplifies future maintenance. When scale has been ignored long enough to damage the exchanger, the noise may continue after flushing, and replacement becomes part of the discussion.

Water hammer and pipe noises

A thud in the walls when a tap or appliance valve closes is water hammer, caused by moving water stopping suddenly. Tankless heaters do not cause it, but quick-closing valves in washers and dishwashers do, and high water pressure makes it worse. Arrestors at the offending fixtures help, and if pressure is high, our water pressure and PRV service can test and adjust the regulator. Rethinking the heater altogether? Storage tank options in Kennesaw are handled by our gas water heater repair and installation service.

If the heater is replaced in Kennesaw

If a noisy heater ends up being replaced, the permit goes through the city's Building Services Department, which takes applications online and can say what a replacement at your address needs before the old unit comes off the wall.

Common questions about tankless noises in Kennesaw

Is it normal for a tankless water heater to make noise after the water is turned off?

Yes, a short period of fan noise after the tap closes is normal on most gas units, as the fan purges leftover exhaust from the combustion chamber and vent. It should stop on its own fairly soon. A fan that runs continuously, or noise that carries on long after the water stops, should be checked.

Why does my tankless heater click several times before it lights?

The igniter is retrying because the control board did not detect a flame on the first attempt. Air in the gas line after work on the piping, low gas pressure, a dirty flame sensor or a weak igniter can all cause it. An occasional extra click is not alarming, but frequent retries or a failure code mean it is time for a service visit.

Can a noisy tankless heater be dangerous?

Most noises point to maintenance or a worn part rather than a hazard. Two exceptions deserve quick action: a bang or pop at ignition, which signals delayed ignition, and any noise accompanied by a gas smell or exhaust odor. In those cases, shut the heater off, keep away from it and call; with a gas smell, leave the house first.

Describing the sound helps

When you call, say when the noise happens, whether at startup, during use or after shutoff, and whether it is getting worse. A short phone recording is surprisingly useful, along with the model number from the label and any code.

For a tankless heater in Kennesaw that has started sounding wrong, Alpha Plumbing and Sewer can take a listen; call (404) 409-4448.