Vacuum Relief Valve for Water Heater

[Neal Lewis]

I was in a condo where the gas water heater was installed at the upper level. With no water running, I was randomly hearing large bubbles of air in the piping and/or heater. There is a newer vacuum relief valve installed on the cold water side supply piping.

Is this normal to have some air entering the valve, even without any water running at any fixtures?

Thanks

[Brandon Whitmore]

Are you sure it wasn't the sound of sediment "popping" when heated in the base of the tank, or condensation dripping onto the burner from a recently lit AWH?

[Neal Lewis]

Brandon, definitely a bubbling noise and not a sizzling or percolating noise. Was very odd.