This often sounds like a percolating coffee maker.
Gas water heater burner noise.
Should there be a sizzling sound but no water visible you may still have a leak.
Here s how sediment causes the noise the sediment traps water underneath it at the bottom of the tank where the gas heating burner is.
The hissing or sizzling sound is that of dripping water on the burners or a small spray of water in the burner area.
Turn off the water.
A water heater making bubbling noise can be traced to debris.
If you are looking for the source for a water heater making noise humming problem you will need to check the heating element.
If you are certain that the noise is from the thermocouple itself and not a variation in the gas burner flame then the most likely explanation is that the thermocouple is not mounted securely against movement.
If you find your water heater is making noise when the hot water is turned on it could be caused.
String the hose to a floor drain or outside.
If the water heater has a leak there may be water standing or dripping in the area around the base.
Generally speaking there is a lower chance of hearing strange noises with a tankless water heater vs tank model.
When that gas burner heats the water it boils and bubbles up until boom it escapes the sediment layer.
Unhealthy mostly yellow gas burner flames top check the gas regulator and air mix that can occur on either lp or propane or natural gas burners.
In a tankless water heater several reasons can create noise.
For a water heater making noises like water running then you will have to check for leaks.
On 2019 11 20 by mm the new thermocouple in my natural gas direct vent fireplace pulsates.
Also see gas regulator noises as problems with gas air mixture can cause noise at the appliance regulator as well as defective gas flame or too low gas flame.
Our guide to what causes a noisy water heater accumulation of sediment mineral deposits.
Flushing the heater should remove the deposits and quiet.
Turn the control knob to pilot on a gas water heater or to off on an electric water heater.
Over time sediment accumulates inside the heater s tank.
When it is heated by the gas burner below moisture in the gunk flashes into steam that bursts into the water.
That s causing the rumbling.
Connect a garden hose to the drain fitting near the bottom of the tank.
Possibility 2 condensating is occurring.
How to fix a popping noise on water heaters 1.
On the other side if the flame becomes starved for air the gas combustion becomes incomplete and will result in sooting.
