Noisy water heaters can mean several things. Water Heater Pros in Sacramento shares tips and valuable information.
Noisy Water Heater
MOST COMMON CAUSE OF WATER HEATER NOISE
Boiling - banging and popping noise is heard, this may be dangerous and should be taken seriously, in most cases your gas water heater has not been serviced (flushed 1 or 2 times a year as recommended) and now has a thick layer of harden mineral deposits in the bottom of the tank trapping water under it. While your heater is fired up and heating usually while washing clothes or taking a shower, this trapped water becomes super heated with temperatures to extreme high's causes the water to boil, even creating steam, this is the noise your hearing.
CAUTION, many people have been severely scolded.
BROKEN DIP TUBE OR ANODE ROD
Inside your hot water heater tank is a plastic dip tube and also a metal anode rod, both of these are known to sometimes break apart and can move around banging against the sides walls of the tank. This has been known to occur in some older units, making popping and banging noise, usually while the water heater is in it's heat cycle.
We recommend replacement of any water heater making these kind of noises.
WHAT CAN HAPPEN?
The super heated water under the layer of mineral deposits (pancake layers), can suddenly cause a rupture in these layers splitting in half the layers of mineral deposits, the super heater water underneath will rapidly rise to the top of the tank where it exits and travels through your piping, and if a shower is being used at the time, can and has caused severe injury.
We recommend replacement of your water heater ASAP if you hear a rumbling and/or poping noise from within your water heater.